Side brush and cleaning robot having a side brush

Abstract

A side brush (140) for a cleaning robot (100) is described, wherein the side brush (140) comprises a hub (142) with a coupling element, and wherein the side brush (140) is designed to be connected to a drive of the cleaning robot (100) via the coupling element in order to effect a rotational movement of the side brush (140) about a rotation axis selectively in a first rotational direction (201) or in an opposite second rotational direction (202). The side brush (140) has a plurality of cleaning arms (141), each of which is fastened to the hub (142) and each of which extends radially away from the hub (142). The side brush (140) is designed such that a tangential force acting perpendicular to the radial direction, which is exerted on a surface to be cleaned by the cleaning arms (141) during a rotational movement of the side brush (140), is higher in the second direction of rotation (202) than in the first direction of rotation (201).

Description

[0001] The invention relates to a side brush for a cleaning robot. Furthermore, the invention relates to a cleaning robot with a side brush.

[0002] A cleaning robot, particularly a vacuum robot, typically has a cleaning unit (e.g., a suction nozzle) with a suction nozzle, through which dirt particles are sucked up from a surface to be cleaned using an air stream. The air stream can be generated by a fan. The air stream transports the dirt particles from the suction nozzle, via a suction channel, into a dirt collection container of the cleaning robot.

[0003] The cleaning robot may further comprise one or more side brushes, which are arranged, for example, laterally next to the suction mouth and which are configured to sweep loose dirt particles along the surface to be cleaned into the suction mouth of the cleaning robot.

[0004] This document deals with the technical task of increasing the cleaning efficiency of one or more side brushes of a cleaning robot.

[0005] The object is achieved by the subject matter of the independent patent claim. Advantageous embodiments are defined in particular in the dependent patent claims, described in the following description, or illustrated in the accompanying drawings.

[0006] According to one aspect, a side brush for a cleaning robot is described. The side brush can be arranged laterally next to the cleaning unit (in particular the suction mouth) of the cleaning robot, in particular to sweep dirt particles toward the cleaning unit.

[0007] The side brush comprises a hub with a coupling element. The side brush is designed to be connected to a drive (e.g., an electric motor) of the cleaning robot via the coupling element in order to effect a rotational movement of the side brush about a rotational axis selectively in a first rotational direction or in an opposite second rotational direction. The rotational axis typically corresponds to the vertical axis of the cleaning robot when the side brush is arranged on the cleaning robot. In other words, the rotational axis can be oriented substantially perpendicular to the surface to be cleaned when the side brush is arranged on the cleaning robot.

[0008] The side brush has a plurality of cleaning arms, each attached to the hub and each extending radially away from the hub. The cleaning arms can be arranged at different angular positions, in particular evenly distributed, around the rotational axis of the side brush. The side brush can have two or more, or three or more cleaning arms. On the other hand, the side brush typically has fewer than ten or fewer than seven cleaning arms. The cleaning arms can comprise bristle tufts and / or one or more rubber arms.

[0009] The side brush can be configured such that a tangential force acting perpendicular to the radial direction, which is exerted by the cleaning arms on a surface to be cleaned during a rotational movement of the side brush, is higher in the second direction of rotation (in particular by 10% or more or by 20% or more) than in the first direction of rotation. Alternatively or additionally, the side brush can be configured such that the flexural rigidity of the cleaning arms is higher in the second direction of rotation (in particular by 10% or more or by 20% or more) than in the first direction of rotation.

[0010] For this purpose, the cleaning arms may have a shape and / or the side brush may have one or more mechanical means by which it is caused that the tangential force exerted by the cleaning arms on a surface to be cleaned during a rotational movement of the side brush is higher in the second direction of rotation than in the first direction of rotation; and / or that the flexural rigidity of the cleaning arms is higher in the second direction of rotation than in the first direction of rotation.

[0011] Thus, a side brush is described that exhibits different cleaning properties for different rotation directions. A relatively high sweeping effect is provided in a first rotation direction, and a more intense effect for loosening dirt particles is provided in a second rotation direction. This allows the cleaning quality of a cleaning robot to be efficiently increased.

[0012] The individual cleaning arms extend along a respective longitudinal direction away from the hub. The individual cleaning arms can have a curved profile along the longitudinal direction, wherein the curved profile of the individual cleaning arms is aligned with the second direction of rotation. The curved profile of the individual cleaning arms can be such that the end of the respective cleaning arm arranged on the hub has an orientation that deviates by a maximum of 10° from the radial direction; and the end of the respective cleaning arm facing away from the hub has an orientation that deviates by a maximum of 30° from the tangential direction.

[0013] By providing cleaning arms that have a curved shape in the unused initial state, a bending stiffness dependent on the direction of rotation can be provided in a particularly efficient manner.

[0014] The individual cleaning arms can each have a first partial arm and a second partial arm, each extending along the longitudinal direction. A gap extending in the longitudinal direction can be arranged between the first partial arm and the second partial arm. This can further enhance the effect of the direction-dependent bending stiffness.

[0015] The side brush can have one or more support elements for each individual cleaning arm, each of which is configured to act on the respective cleaning arm at at least one point along the longitudinal direction in order to impede a tangential movement of the cleaning arm in the tangential direction. The one or more support elements for a cleaning arm can each be configured such that the tangential movement of the cleaning arm is impeded more strongly in the first direction of rotation than in the second direction of rotation.

[0016] Using one or more support elements, the freely movable length of the individual cleaning arms can be changed, particularly reduced, depending on the direction of rotation. This allows for a particularly efficient and reliable way to provide bending stiffness that is dependent on the direction of rotation.

[0017] The one or more support elements for a cleaning arm can each comprise a sleeve that at least partially encloses the cleaning arm along a specific length in the longitudinal direction, starting from the hub. The flexural rigidity of the cleaning arm can then be determined by the length of the sleeve.

[0018] The sleeve for a cleaning arm can be closed on the side facing the first direction of rotation and can be open on the side facing the second direction of rotation. Alternatively or additionally, the sleeve for a cleaning arm can have a greater length along the longitudinal direction on the side facing the first direction of rotation than on the side facing the second direction of rotation. In this way, a rotation-direction-dependent bending stiffness can be provided in a particularly efficient and reliable manner.

[0019] The side brush can comprise a ring on which at least one support element (e.g., in the form of a tooth or a bolt) is arranged for each cleaning arm. The ring can be designed to be movable, particularly along the rotation axis, so that a movement of the ring can cause the support elements arranged on the ring to act on the respective cleaning arm or not. The movement of the ring can, if necessary, be caused by an actuator of the cleaning robot. In this way, a bending stiffness dependent on the direction of rotation can be provided in a particularly convenient and reliable manner.

[0020] The side brush can comprise a first ring, on which a support element is arranged for each cleaning arm, which support element is designed to hinder the tangential movement of the cleaning arm in the tangential direction when the side brush is rotated in the first direction of rotation. Furthermore, the side brush can comprise a second ring, on which a support element is arranged for each cleaning arm, which support element is designed to hinder the tangential movement of the cleaning arm in the tangential direction when the side brush is rotated in the second direction of rotation. The first ring can have a smaller diameter (e.g., by 10% or more, or by 20% or more) than the second ring. In this way, a bending stiffness dependent on the direction of rotation can be provided in a particularly efficient and reliable manner.

[0021] The support element for a cleaning arm can be designed such that the tangential distance of the support element (in the tangential direction) to the cleaning arm can be varied in several stages or continuously. The side brush can be designed such that the change in the tangential distance of the support element to the cleaning arm can be effected automatically by an actuator of the cleaning robot. This allows for a rotation-direction-dependent bending stiffness to be provided in a particularly convenient and precise manner.

[0022] The individual cleaning arms may each be connected to the hub via a joint, whereby the joint enables a pivoting movement of the respective cleaning arm about a pivot axis that runs parallel and offset to the axis of rotation.

[0023] The joint for a cleaning arm can be designed to limit the pivoting movement of the cleaning arm by a first stop when the side brush is rotated in the first direction of rotation so that the cleaning arm has a first orientation; and to limit the pivoting movement of the cleaning arm by a second stop when the side brush is rotated in the second direction of rotation so that the cleaning arm has a second orientation.

[0024] In this case, a cleaning arm can extend further along the radial direction in the second orientation than in the first orientation. Alternatively or additionally, the second orientation can deviate less from the radial direction than the first orientation. This allows for a particularly efficient and reliable provision of flexural rigidity dependent on the direction of rotation.

[0025] According to one aspect, a cleaning robot for cleaning a surface (e.g., a floor) is described. The cleaning robot can be designed to move independently over the surface to be cleaned. For this purpose, the cleaning robot comprises a drive designed to move the cleaning robot along a direction of movement over the surface to be cleaned. The cleaning robot comprises a cleaning unit designed to be moved over the surface. The cleaning unit can have a suction mouth and, if appropriate, a brush roller. The cleaning unit is designed to pick up dirt particles from the surface to be cleaned.

[0026] The cleaning robot further comprises at least one side brush configured as described in this document. The side brush can be arranged laterally next to (and optionally in front of) the cleaning unit with respect to the direction of movement. The cleaning robot can optionally have a side brush on each side (i.e., to the right and left of) the cleaning unit.

[0027] The one or more side brushes can each be designed such that, when the respective side brush rotates in the first direction of rotation, the cleaning arms of the side brush move from the front towards the cleaning unit, in particular counter to the direction of movement, and / or that, when the respective side brush rotates in the second direction of rotation, the cleaning arms of the side brush move forward away from the cleaning unit, in particular along the direction of movement.

[0028] When using one side brush each on each side of the cleaning unit, the side brushes are preferably constructed with mirror symmetry to one another. For the side brush on the left side, the first direction of rotation can be clockwise and the second direction of rotation can be counterclockwise. For the side brush on the right side, the first direction of rotation can be counterclockwise and the second direction of rotation can be clockwise. The coupling elements of the two side brushes can be designed differently, in particular coded, to ensure that a side brush intended for the right side can only be attached to the right side and that a side brush intended for the left side can only be attached to the left side.

[0029] The cleaning robot may include a control unit configured to determine whether the side brush should be operated in a dirt-sweeping mode or a dirt-loosening mode. This may be determined, for example, based on user input and / or based on an analysis of the area to be cleaned.

[0030] The control unit may be configured to cause the side brush to rotate in the first direction of rotation when it has been determined that the side brush should be operated in the dirt-sweeping mode. Furthermore, the control unit may be configured to cause the side brush to rotate in the second direction of rotation when it has been determined that the side brush should be operated in the dirt-removing mode.

[0031] In this way, the cleaning quality of a cleaning robot can be reliably increased.

[0032] According to a further aspect, a method for cleaning a surface in an area (e.g., in a room) is described using a cleaning robot, wherein the cleaning robot is designed as described in this document. The method comprises identifying a first sub-area in which the dirt particles are to be swept from the surface and a second sub-area in which dirt particles are to be removed from the surface (e.g., based on sensor data from one or more environmental sensors of the cleaning robot). Furthermore, the method comprises causing the side brush of the cleaning robot to rotate in the first direction of rotation in the first sub-area, and causing the side brush of the cleaning robot to rotate in the second direction of rotation in the second sub-area.

[0033] It should be noted that any aspects of the cleaning robot described in this document and / or the side brush for a cleaning robot described in this document and / or the method described in this document can be combined in a variety of ways. In particular, the features of the patent claims can be combined in a variety of ways.

[0034] The invention will be described in more detail below with reference to exemplary embodiments illustrated in the accompanying drawings. Figures 1a and 1b an exemplary cleaning robot in different perspective views; Figure 1c exemplary components of a cleaning robot; Figures 2a to 2c different views of a side brush with curved cleaning arms; Figures 3a to 3d different views of a side brush with one-sided supported cleaning arms; Figures 4a to 4hdifferent views of a side brush with support elements to support the cleaning arms; Figures 5a to 5f different views of a side brush with pivoting cleaning arms; and Figure 6 a flowchart of an exemplary method for cleaning a surface in an area.

[0035] As stated at the beginning, this document deals with improving the cleaning quality of a cleaning device, in particular a cleaning robot. In this context, Fig. 1a the top 121 and Fig. 1b the underside 122 of a cleaning robot 100, in particular a vacuum robot. The aspects described in connection with a cleaning robot are generally applicable to a cleaning device.

[0036] During vacuuming operation of the cleaning robot 100, the underside 122 faces the floor to be cleaned or the surface of a cleaning area, such as a room, to be cleaned. The underside 122 of the cleaning robot 100 typically has one or more drive units 101 (typically with one or more drive wheels), by means of which the cleaning robot 100 can be moved independently to clean different areas of a floor. Furthermore, the cleaning robot 100 can have one or more guide and / or support elements 104 (e.g., non-driven wheels) that enable stable movement of the cleaning robot 100 over the floor to be cleaned. In addition, a cleaning robot 100 typically comprises one or more cleaning units 106 (in particular, suction nozzles) that are configured to clean the floor beneath the cleaning robot 100.

[0037] A cleaning unit 106 (in particular a suction nozzle) may include a brush roller 102 configured to rotate about a rotation axis, wherein the rotation axis is typically arranged parallel to the underside 122 of the cleaning robot 100. The brush roller 102 may be used to mechanically remove dust and / or contaminants from the floor to be cleaned, so that the dust and / or contaminants can be sucked into the suction mouth 107 of the cleaning unit 106 with increased reliability.

[0038] A user interface can be arranged on the top side 121 of the cleaning robot 100, which allows a user of the cleaning robot 100 to make control inputs. Furthermore, the cleaning robot 100 can comprise a bumper 105 on a side wall 123 (e.g., on a side wall 123 in the front area of ​​the cleaning robot 100). A bumper sensor can be arranged on the bumper 105 and is configured to capture sensor data indicating whether or not the cleaning robot 100 has encountered an obstacle in the direction of movement 120. Triggering the bumper sensor (due to the deflection of the bumper 105) by an obstacle can, for example, cause the cleaning robot 100 to rotate about its vertical or vertical axis, which is perpendicular to the floor, and thereby change the direction of movement 120 to avoid the obstacle.

[0039] Furthermore, a cleaning robot 100 typically has one or more environment sensors 110 (see Fig. 1c) that are configured to capture environmental or sensor data relating to the environment of the cleaning robot 100. The one or more environmental sensors 110 can include: one or more image cameras, one or more ultrasonic sensors, one or more tactile and / or optical distance sensors, one or more acoustic sensors, one or more temperature sensors, one or more lidar and / or radar sensors, etc. A control unit 130 of the cleaning robot 100 can be configured to determine digital map information relating to the cleaning area to be cleaned based on the environmental data and, if necessary, to store it on a storage unit 111 of the cleaning robot 100. The cleaning robot 100 can use the digital map information to independently orient itself within the cleaning area (e.g., within a room) and / or to determine a route for cleaning the cleaning area.

[0040] Fig. 1cshows a Cartesian coordinate system with a longitudinal axis (i.e., an x-axis), a transverse axis (i.e., a y-axis), and a vertical axis (i.e., a z-axis). The direction of movement 120 of the cleaning device 100 typically corresponds to the longitudinal axis. The axis of rotation of the brush roller 102 typically runs along the transverse axis. The cleaning device 100 typically has a collecting container 150, which can be inserted into a container recess of the cleaning device 100 or removed from the container recess of the cleaning device 100.

[0041] The cleaning robot 100 may have one or more side brushes 140, each of which is designed to sweep dirt particles toward the cleaning unit 106, in particular toward the suction mouth 107. In the Figures 1a and 1bIn the example shown, the cleaning robot 100 has a side brush 140 arranged laterally next to the cleaning unit 106. Furthermore, the side brush 140 can be arranged in front of the cleaning unit 106 with respect to the direction of movement 120 of the cleaning robot 100. If necessary, a side brush 140 can be arranged on each side of the cleaning unit 106.

[0042] A side brush 140 comprises a hub 142, which is designed to be connected to a drive unit (not shown) of the cleaning robot 100 via a coupling element. The hub 142 can be rotated about a rotation axis by the drive unit. Several cleaning arms 141 are arranged on the hub 142 and extend radially away from the hub 142. The rotational movement of the hub 142 guides the cleaning arms 141 over the surface to be cleaned. The cleaning arms 141 can sweep loose dirt particles along the surface to be cleaned toward the cleaning unit 106.

[0043] The cleaning arms 141 of a side brush 140 typically consist of relatively soft bristles, which ensures a particularly reliable sweeping action of the cleaning arms 141. On the other hand, the use of relatively soft bristles allows only relatively low tangential forces to be exerted on the surface to be cleaned, so that dirt particles adhering to the surface to be cleaned usually cannot be removed by the rotating side brush 140.

[0044] This document describes a side brush 140 with cleaning arms 141, which are configured to exert tangential forces of varying magnitudes on the surface to be cleaned depending on the direction of rotation of the side brush 140. The tangential forces can act in a tangential direction perpendicular to the radial direction of the side brush 140 (i.e., the circumferential direction of the hub 142).

[0045] The side brush 140 can, in particular, be configured to exert tangential forces with a first force value in a first rotational direction and with a second force value in the opposite second rotational direction. The first force value can be lower than the second force value (e.g., by 10% or more, or by 20% or more). As a result, relatively small tangential forces are exerted on the surface to be cleaned and / or the individual cleaning arms 141 have a relatively high "softness" when the side brush 140 is rotated in the first rotational direction. This allows for a reliable sweeping action. On the other hand, relatively high tangential forces are exerted on the surface to be cleaned when the side brush 140 is rotated in the second rotational direction. This allows for reliable removal of dirt particles from the surface to be cleaned.

[0046] Fig. 2a to 2cshow different views of a side brush 140 having curved cleaning arms 141, each extending away from the hub 142. The side brush 140 can be rotated around the hub 142 in a first rotational direction 201 and in an opposite second rotational direction 202. The cleaning arms 141 can move from the front towards the suction mouth 107 of the cleaning robot 100 in the first rotational direction 201. On the other hand, the cleaning arms 141 can move forward away from the suction mouth 107 in the second rotational direction 202. The first rotational direction 201 can be used to sweep dirt particles towards the suction mouth 107. On the other hand, the second rotational direction 202 can be used to loosen dirt particles from the surface to be cleaned. The loosened dirt particles can then be swept to the suction mouth 107 in a subsequent step.For example, in a subsequent step, the side brush 140 can be caused to rotate in the first direction of rotation 201 in order to sweep the previously loosened dirt particles to the suction mouth 107.

[0047] The individual cleaning arms 141 have a curvature, so that the cleaning arms 141 each have a course that extends in the radial direction and in the tangential direction. A cleaning arm 141 has a longitudinal direction that extends from the hub-side end of the cleaning arm 141 (which is arranged on the hub 142) to the remote end of the cleaning arm 141 (which is remote from the hub 142). The longitudinal direction of the cleaning arm 141 can correspond to the radial direction at the hub-side end. With increasing distance from the hub 142, the longitudinal direction of the cleaning arm 141 can increasingly be aligned towards the tangential direction, possibly such that the remote end of the cleaning arm 141 is aligned substantially in the tangential direction.

[0048] The individual cleaning arms 141 are bent such that the opposite ends of the individual cleaning arms 141 each face away from the first direction of rotation 201 and / or face the second direction of rotation 202. Such a pre-curvature of the individual cleaning arms 141 results in the forces acting on the individual cleaning arms 141 bending the individual cleaning arms 141 further away from the first direction of rotation 201 when the side brush 140 rotates in the first direction of rotation 201, thereby reducing the overall tangential forces exerted by the cleaning arms 141 on the surface to be cleaned.

[0049] On the other hand, the pre-curvature of the individual cleaning arms 141 causes the forces acting on the individual cleaning arms 141 to straighten the individual cleaning arms 141 when the side brush 140 rotates in the second direction of rotation 202, so that the total tangential forces exerted by the cleaning arms 141 on the surface to be cleaned are increased or at least not reduced.

[0050] A cleaning arm 141 can have a plurality of partial arms 211, 212, each extending along the longitudinal direction of the cleaning arm 141. A gap 213 can be arranged between each of the individual partial arms 211, 212. By using a plurality of partial arms 211, 212, the bending effect (when rotating in the first rotational direction 201) and / or the straightening effect (when rotating in the second rotational direction 202) can be further enhanced, thereby further improving the sweeping effect (when rotating in the first rotational direction 201) and the effect of loosening dirt particles (when rotating in the second rotational direction 202) of the side brush 140.

[0051] In the Figures 3a to 3dA side brush 140 is shown, which has a support element 311 for each individual cleaning arm 141, which support element is designed to support the respective cleaning arm 141 when the side brush 140 rotates in the second rotational direction 202. On the other hand, the respective cleaning arm 141 is essentially not supported by the support element 311 when the side brush 140 rotates in the first rotational direction 201. The support element 311 can extend radially along the longitudinal direction of the cleaning arm 141. The support element 311 can have a specific length 313 in the radial direction, wherein the length 313 can change the rotational direction-selective supporting effect of the support element 311.

[0052] When the side brush 140 is rotated in the first rotational direction 201, the cleaning arms 141 are bent tangentially toward the second rotational direction 202, thereby reducing the tangential forces exerted by the individual cleaning arms 141 on the surface to be cleaned. When the side brush 140 is rotated in the second rotational direction 202, the cleaning arms 141 are supported tangentially by the respective support elements 311, so that the individual cleaning arms 141 are bent only to a reduced extent tangentially toward the first rotational direction 201, resulting in relatively high tangential forces exerted by the individual cleaning arms 141 on the surface to be cleaned.

[0053] In the Figures 4a to 4hA side brush 140 is shown, which has one or more support elements 401, 402 for each cleaning arm 140, which can be retracted or extended as required. The individual support elements 401, 402 are arranged radially spaced from the hub 142. The supporting effect of a support element 401, 402 typically increases with increasing distance from the hub 142.

[0054] A support element 401, 402 for a cleaning arm 141 can cause the cleaning arm 141 to bend to varying degrees depending on the direction of rotation 201, 202 of the side brush 140, thus exerting varying tangential forces on the surface to be cleaned depending on the direction of rotation 201, 202. For each cleaning arm 141, a (retractable) support element 401, 402 can be provided for each of the two directions of rotation 201, 202, if necessary.

[0055] The provision of a retractable support element 401, 402 makes it possible to change the flexural rigidity of a cleaning arm 141 even while maintaining the same direction of rotation 201, 202. When the support element 401, 402 is retracted, the cleaning arm 141 has a relatively low flexural rigidity. On the other hand, when the support element 401, 402 is extended, the cleaning arm 141 has a relatively high flexural rigidity. Fig. 4f By way of example, a retracted support element 402 is shown, which does not support a cleaning arm 141 when the side brush 140 rotates in the first direction of rotation 201, so that a relatively good sweeping effect can be achieved with the cleaning arm 141. In Fig. 4g The same support element 402 is extended, so that the cleaning arm 141 is supported by it when the side brush 140 rotates in the first rotation direction 201. In this case, the cleaning arm 141 has a more effective removal of dirt particles.

[0056] In the Figures 5a to 5f A side brush 140 is shown in which the individual cleaning arms 141 are each attached to the hub 142 via a joint 513. The joint 513 enables a pivoting movement of the cleaning arm 141 between a first stop 511 and a second stop 512. The cleaning arm 141 can be arranged at the first stop 511 by rotating the side brush 140 in the first rotational direction 201. On the other hand, the cleaning arm 141 can be arranged at the second stop 512 by rotating the side brush 140 in the second rotational direction 202.

[0057] The first stop 511 and the second stop 512 can be configured such that the longitudinal direction of the cleaning arm 141 is more oriented in the tangential direction when the cleaning arm 141 is arranged at the first stop 511 than when the cleaning arm 141 is arranged at the second stop 512. This can cause the tangential forces exerted by the cleaning arm 141 to be higher when the cleaning arm is arranged at the second stop 512 than when the cleaning arm 141 is arranged at the first stop 511.

[0058] Thus, a side brush 140 is described which is designed such that the side brush 140 has a different stiffness depending on the direction of rotation 201, 202. The side brush 140 can have increased stiffness, particularly in a second direction of rotation 202, so that dirt can be removed from the floor when the side brush 140 is rotated in the second direction of rotation 202. The side brush 140 can also be designed such that the effective diameter of the side brush 140 can be changed, in particular, can be enlarged depending on the situation, for example, to be able to reach narrow passages that are impassable.

[0059] The cleaning robot 100 can be a vacuum and / or sweeping robot, which can have an optional wet cleaning module. The cleaning robot 100 can have a brush roller 102 rotating about a horizontal axis for sweeping up relatively coarse dirt particles and / or a suction fan for sucking in fine dust particles. Collected dust and dirt can be stored in a collection container 150. A rotating side brush 140 can be arranged on at least one front corner of the housing of the cleaning robot 100.

[0060] In standard operation, the side brush 100 rotates at its front edge toward the center of the cleaning robot 100, i.e., a side brush 140 positioned at the front right in the direction of travel 120 rotates counterclockwise and / or a side brush 140 positioned at the front left in the direction of travel 130 rotates clockwise. This direction of rotation is referred to in this document as the first direction of rotation 201. In this standard direction of rotation 201, the cleaning arms 141 of the side brush 140 have comparatively low flexural rigidity. The side brush 140 appears "soft" and "supple" and therefore has relatively good sweeping properties (even for relatively fine dust particles).

[0061] The side brush 140 can be designed so that the cleaning arms 141 have a clearly curved shape (as shown for example in the Figures 2a to 2c(shown). The bend runs predominantly in the horizontal plane, so that the side brush 140 resembles a spiral when viewed along the rotation axis of the side brush 140. With respect to the standard direction of rotation 201 of the side brush 140, the cleaning arms 141 are bent opposite to the standard direction of rotation 201. The bend can be combined with a (section-by-section) outward tapering of the cleaning arms 141. The cleaning arms 141 preferably do not have any significantly rectilinear sections.

[0062] When the side brush 140 rotates, frictional forces act on the cleaning arms 141 caused by contact with the floor. In the standard direction of rotation 201, the cleaning arms are pressed in the predetermined curved direction. There is relatively little resistance in the individual cleaning arms 141, so that the individual cleaning arms 141 bend further relatively easily and thus have a relatively low bending stiffness in this direction of rotation 201. When rotating counter to the standard direction of rotation, i.e., when rotating in the second direction of rotation 202, the frictional forces act counter to the predetermined bending, so that the individual cleaning arms 141 support themselves against bending, resulting in increased bending stiffness of the side brush 141.

[0063] Alternatively or additionally, different bending stiffnesses for different directions of rotation 201, 202 can be achieved by an external, asymmetrical support of the cleaning arms 141 (as shown for example in the Figures 3a to 3dshown). This concept is suitable for side brushes 140 with bristle tufts and for side brushes 140 with rubber arms. A supporting sleeve 311 (i.e., a support element) is arranged around the actual (base) cleaning arm 141, which supports the cleaning arm 141 to different extents (along the longitudinal direction of the cleaning arm 141) depending on the direction of rotation 201, 202. The sleeve 311 can, for example, be designed only half-sided, so that the sleeve 313 supports the cleaning arm 141 only in one direction of rotation 202, while the cleaning arm 141 is not supported at all in the other direction of rotation 201. Depending on the direction of rotation 201, 202, the bending stiffnesses result from the material properties of the cleaning arm 141 and the unsupported length of the cleaning arm 141. The shorter the unsupported length of the cleaning arm 141, the higher the bending stiffness.

[0064] For rotation of the side brush 140 in the standard direction of rotation 201, the cleaning arms 141 are preferably supported only slightly or not at all to allow bending along their entire length. The cleaning arms 141 then have low resistance, appear "soft," and exhibit relatively good sweeping properties for fine particles. In the opposite direction of rotation 202, the cleaning arms 141 are preferably supported over a significant length 313 to shorten the "effective length" of the cleaning arms 141. The flexural rigidity thus increases noticeably.

[0065] In an extended form, the sleeve 311 can have a variable length 313 for support, so that a (stepwise or continuously variable) adjustment of the flexural rigidity can be carried out even during operation of the cleaning robot 100 (automatically) and with a constant direction of rotation 202 of the side brush 140.

[0066] Alternatively or additionally, the external support of the cleaning arms 141 can be provided by a comb (as shown for example in the Figures 4a to 4hThis comb can be circular in shape as a "toothed crown" and act on the cleaning arms 141, for example, from above. Where the comb (in particular the teeth 401, 402 of the comb) touches the cleaning arms 141, the cleaning arms 141 are supported, so that their effective length is shortened and their flexural rigidity increases. The diameter of the comb (also referred to as a ring in this document) determines the effective length of the cleaning arms 141. The comb can act on the individual cleaning arms 141 from one side or from both sides. The comb can be designed with several rows of teeth arranged on different rings, each with a different diameter. The teeth 401, which each act on the cleaning arms 141 from a first side, can be arranged on a circular ring with a significantly different diameter than the teeth 402, which each act on the cleaning arms 141 from the other side.

[0067] A change in the flexural rigidity of the cleaning arms 141 while maintaining the standard rotation direction 201 of the side brush 140 can be achieved by designing the comb so that it can be moved closer to the cleaning arms 141 as needed. For example, the comb can be designed so that it can be lowered onto the side brush 140 from above (along the rotation axis of the side brush 140). When the comb is retracted (above the side brush 140), the cleaning arms 141 can bend freely and appear "soft." When the comb is extended (comb teeth 401, 402 at the level of the cleaning arms 141), the comb supports the cleaning arms 141, shortening their effective length and thus increasing their flexural rigidity.

[0068] Alternatively or additionally, a comb can be used whose teeth 401, 402 can be moved tangentially away from or toward the individual cleaning arms 141. If the comb teeth 401, 402 distance themselves from the cleaning arms 141, the latter can bend more easily. If the comb teeth 401, 402 approach the cleaning arms 141 or touch them, bending is made more difficult or impossible, and the flexural rigidity increases.

[0069] Alternatively or additionally, the individual support elements 401, 402 (in particular teeth) can each be configured to be moved in the radial direction. By moving the individual support elements 401, 402 along the radial direction (possibly smoothly or stepwise), the effective length of the individual cleaning arms 141 can be changed (smoothly or stepwise) in order to change the flexural rigidity of the individual cleaning arms 141 (smoothly or stepwise).

[0070] Alternatively or additionally, different effective bending stiffnesses can be achieved depending on the direction of rotation 201, 202 by using swivel joints or flexible joint points 513 on the cleaning arms 141 and stops 511, 512 to limit the joint movement (see Figures 5a to 5f). The changed bending stiffness is based on the resistance that the cleaning arms 141 can exert at a certain angle against a tangential external force. Thus, in the standard direction of rotation 201, a cleaning arm 141 can rotate at the pivot point 513 through a certain angle of rotation before the cleaning arm 141 is held by the first stop 511. Depending on the angle of rotation, the cleaning arm 141 only sweeps over the floor without offering or exhibiting any appreciable bending resistance. In the opposite direction of rotation 202, the second stop 512 can hold the cleaning arm 141 at an angle that is almost perpendicular to the side brush 140 (i.e., from the hub 142 of the side brush 140). The cleaning arm 141 now bends due to the frictional forces on the floor and therefore displays increased bending stiffness.

[0071] The pivot joints or articulation points 513 on the cleaning arms 141 are typically not coaxial with the rotation axis of the side brush 140. Furthermore, the cleaning arms 141 do not support each other, but are each held by stops 511, 512 which are arranged on the side brush 140 and on the central body (ie the hub) 142 of the side brush 140, respectively.

[0072] The measures described in this document make it possible to use a single side brush 140 to sweep fine dust and loose particles, on the one hand, and to remove stubborn dirt from the floor in places that the main brush 102 cannot reach, on the other. This can be achieved by increasing the flexural rigidity depending on the direction of rotation.

[0073] By varying the flexural rigidity, different "softnesses" of the cleaning arms 141 can be achieved, which are reflected in changed sweeping properties that are advantageous depending on the type of dirt or particle size.

[0074] The varying deflection of the cleaning arms 141 (depending on the direction of rotation 201, 202) can result in the side brush 140 having different effective diameters depending on the direction of rotation 201, 202, allowing the use of side brush properties adapted to specific situations. Different effective diameters are associated with different peripheral speeds of the side brush 140, which can be used to achieve optimized sweeping effects for specific types of dirt (coarse dirt or fine dust).

[0075] Thus, a side brush 140 is described that enables the removal of stubborn or adhering dirt from surfaces. For this purpose, the cleaning arms 141 of the side brush 140 have different stiffnesses for the two directions of rotation 201, 202 of the side brush 140. This can be achieved by geometric means (e.g., spiral arms) and / or mechanical means. When the direction of rotation is reversed, the side brush 140 thus has greater stiffness, allowing stubborn dirt to be removed.

[0076] The control unit 130 of the cleaning robot 100 can be configured to identify a specific location where dirt is to be removed from the floor based on the sensor data from the one or more sensors 110 (e.g., a camera) and / or based on navigation data (e.g., a digital map for the area to be cleaned). The one or more side brushes 140 can then be operated at the identified location in the second rotation direction 202 to remove the dirt from the floor.

[0077] Fig. 6 shows a flowchart of a (possibly computer-implemented) method 600 for (spot) cleaning a surface in an area using a cleaning robot 100, wherein the cleaning robot 100 is designed as described in this document.

[0078] The method 600 includes identifying 601 a first sub-area of ​​the area in which the dirt particles are to be swept from the surface and a second sub-area of ​​the area in which the dirt particles are to be removed from the surface. This can be accomplished based on the sensor data from one or more environmental sensors 110 of the cleaning robot 100.

[0079] The method 600 further includes causing 602 the side brush 140 of the cleaning robot 100 to perform a rotational movement in the first rotational direction 201 in the first sub-area, and causing the side brush 140 of the cleaning robot 100 to perform a rotational movement in the second rotational direction 202 in the second sub-area. Thus, the two sub-areas can be cleaned with particularly high quality.

[0080] The method 600 may further comprise causing the side brush 140 of the cleaning robot 100 to be operated in the second sub-area with a rotational movement in the first rotational direction 201 in a subsequent step (following the operation with a rotational movement in the second rotational direction 202). Thus, the previously loosened dirt in the second sub-area can be reliably swept away.

[0081] To clean a partial area, the side brush 140 of the cleaning robot 100 can thus first be operated with a rotational movement in the second rotational direction 202 (to loosen dirt) and subsequently (in the same partial area) with a rotational movement in the first rotational direction 201. This allows for particularly thorough cleaning.

[0082] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the cleaning robot described in this document and / or the side brush described in this document and / or the method described in this document. List of reference symbols

[0083] 100Cleaning device (cleaning robot) 101Drive unit 102Brush roller 104Guide and / or support element 105Bumper 106Cleaning unit / suction nozzle 107Suction mouth 110Environment sensor 111Storage unit 120Direction of movement / longitudinal direction 121Top 122Bottom 123Side wall 130Control unit 140Side brush 141Cleaning arm 142Hub (of the side brush) 150Collection container / dust box 201First direction of rotation 202Second direction of rotation 211First partial arm 212Second partial arm 213Gap between the partial arms 311Support element (sleeve) 313Radial length of the support element 401Support element 402Support element 511First stop 512second stop 513joint 600process 601, 602process step

Claims

1. A side brush (140) for a cleaning robot (100), wherein - the side brush (140) comprises a hub (142) with a coupling element; - the side brush (140) is designed to be connected to a drive of the cleaning robot (100) via the coupling element in order to effect a rotational movement of the side brush (140) about a rotational axis selectively in a first rotational direction (201) or in an opposite second rotational direction (202); - the rotational axis corresponds to a vertical axis of the cleaning robot (100) when the side brush (140) is arranged on the cleaning robot (100); - the side brush (140) has a plurality of cleaning arms (141), each of which is fastened to the hub (142) and each of which extends radially away from the hub (142);and - the side brush (140) is designed such that a tangential force acting perpendicular to the radial direction, which is exerted on a surface to be cleaned by the cleaning arms (141) during a rotational movement of the side brush (140), is higher in the second direction of rotation (202) than in the first direction of rotation (201); 2. Side brush (140) according to claim 1, wherein the side brush (140) is designed such that a flexural rigidity of the cleaning arms (141) in the second direction of rotation (202) is higher than in the first direction of rotation (201).

3. Side brush (140) according to one of the preceding claims, wherein the cleaning arms (141) have a shape and / or wherein the side brush (140) has one or more mechanical means by which the tangential force exerted by the cleaning arms (141) on a surface to be cleaned during a rotational movement of the side brush (140) is higher in the second direction of rotation (202) than in the first direction of rotation (201).

4. Side brush (140) according to one of the preceding claims, wherein - the individual cleaning arms (141) extend along a respective longitudinal direction away from the hub (142); - the individual cleaning arms (141) have a curved course along the longitudinal direction; and - the curved course of the individual cleaning arms (141) is aligned with the second direction of rotation (202).

5. Side brush (140) according to claim 4, wherein the curved course of the individual cleaning arms (141) is such that - an end of the respective cleaning arm (141) arranged on the hub (142) has an orientation that deviates by at most 10° from the radial direction; and - an end of the respective cleaning arm (141) facing away from the hub (142) has an orientation that deviates by at most 30° from the tangential direction.

6. Side brush (140) according to one of the preceding claims, wherein - the individual cleaning arms (141) extend along a respective longitudinal direction away from the hub (142); - the individual cleaning arms (141) each have a first partial arm (211) and a second partial arm (212), each extending along the longitudinal direction; and - a longitudinally extending gap (213) is arranged between the first partial arm (211) and the second partial arm (212).

7. Side brush (140) according to one of the preceding claims, wherein - the individual cleaning arms (141) extend away from the hub (142) along a respective longitudinal direction; - the side brush (140) for the individual cleaning arms (141) each has one or more support elements (311, 401, 402), which are each designed to act on the respective cleaning arm (141) at at least one point along the longitudinal direction in order to hinder a tangential movement of the cleaning arm (141) in the tangential direction; and - the one or more support elements (311, 401, 402) for a cleaning arm (141) are designed such that the tangential movement of the cleaning arm (141) is hindered more towards the first direction of rotation (201) than towards the second direction of rotation (202).

8. Side brush (140) according to claim 7, wherein the one or more support elements (311, 401, 402) for a cleaning arm (141) comprise a sleeve (311) which at least partially encloses the cleaning arm (141) starting from the hub (142) along a certain length (313) along the longitudinal direction.

9. Side brush (140) according to claim 8, wherein the sleeve (311) is closed on the side facing the first direction of rotation (201) and is open on the side facing the second direction of rotation (202).

10. Side brush (140) according to one of claims 8 to 9, wherein the sleeve (311) has a greater length (313) along the longitudinal direction on the side facing the first direction of rotation (201) than on the side facing the second direction of rotation (202).

11. Side brush (140) according to one of claims 7 to 10, wherein - the cleaning arms (141) are arranged at different angular positions, in particular evenly distributed, around the axis of rotation of the side brush (140); - the side brush (140) comprises a ring on which at least one support element (401, 402) is arranged for each cleaning arm (141); and - the ring is designed to be movable, in particular along the axis of rotation, so that a movement of the ring can cause the support elements (401, 402) arranged on the ring to act on the respective cleaning arm (141) or not to act on it.

12. Side brush (140) according to one of claims 7 to 11, wherein - the side brush (140) comprises a first ring, on which a support element (402) is arranged for each cleaning arm (141), which support element is designed to hinder the tangential movement of the cleaning arm (141) in the tangential direction when the side brush (140) is rotated in the first direction of rotation (201); - the side brush (140) comprises a second ring, on which a support element (401) is arranged for each cleaning arm (141), which support element is designed to hinder the tangential movement of the cleaning arm (141) in the tangential direction when the side brush (140) is rotated in the second direction of rotation (202); and - the first ring has a smaller diameter than the second ring.

13. Side brush (140) according to one of claims 7 to 12, wherein - a support element (311, 401, 402) for a cleaning arm (141) is designed such that a tangential distance of the support element (311, 401, 402) to the cleaning arm (141) can be changed in several stages or continuously; and - the side brush (140) is designed in particular such that the change in the tangential distance of the support element (311, 401, 402) to the cleaning arm (141) can be effected automatically by an actuator of the cleaning robot (100).

14. Side brush (140) according to one of the preceding claims, wherein - the individual cleaning arms (141) are each connected to the hub (142) via a joint (513) that enables a pivoting movement of the respective cleaning arm (141) about a pivot axis that runs parallel and offset to the axis of rotation; - the joint (513) is designed for a cleaning arm (141), - to limit the pivoting movement of the cleaning arm (141) by a first stop (511) when the side brush (140) is rotated in the first direction of rotation (201), so that the cleaning arm (141) has a first orientation; and - to limit the pivoting movement of the cleaning arm (141) by a second stop (512) when the side brush (140) is rotated in the second direction of rotation (202), so that the cleaning arm (141) has a second orientation;and - a cleaning arm (141) extends further along the radial direction in the second orientation than in the first orientation; and / or - the second orientation deviates less from the radial direction than the first orientation.; 15. A cleaning robot (100) for cleaning a surface; wherein the cleaning robot (100) comprises - a drive (101) configured to move the cleaning robot (100) along a direction of movement (120) over a surface to be cleaned; - a cleaning unit (106) configured to collect dirt particles from the surface to be cleaned; and - a side brush (140) configured according to one of the preceding claims and arranged laterally next to the cleaning unit (106) with respect to the direction of movement (120), so that - upon a rotational movement of the side brush (140) in the first direction of rotation (201), the cleaning arms (141) of the side brush (140) move from the front onto the cleaning unit (106), in particular counter to the direction of movement (120);and - when the side brush (140) rotates in the second direction of rotation (202), the cleaning arms (141) of the side brush (140) move forward away from the cleaning unit (106), in particular along the direction of movement (120); 16. The cleaning robot (100) according to claim 15, wherein the cleaning robot (100) comprises a control unit (130) configured to determine whether the side brush (140) is to be operated in a dirt-sweeping mode or in a dirt-removing mode; and to cause the side brush (140) to rotate in the first rotational direction (201) if it has been determined that the side brush (140) is to be operated in the dirt-sweeping mode; and the side brush (140) to rotate in the second rotational direction (202) if it has been determined that the side brush (140) is to be operated in the dirt-removing mode.

17. A method (600) for cleaning a surface in an area by means of a cleaning robot (100) designed according to one of claims 15 to 16; wherein the method (600) comprises - identifying (601) a first partial area in which the dirt particles are to be swept from the surface and a second partial area in which dirt particles are to be removed from the surface; and - causing (602) that - the side brush (140) of the cleaning robot (100) executes a rotational movement in the first rotational direction (201) in the first partial area; and - the side brush (140) of the cleaning robot (100) executes a rotational movement in the second rotational direction (202) in the second partial area.

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