Side brush and cleaning robot having a side brush

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, especially a robotic vacuum cleaner, typically has a cleaning unit (e.g., a suction nozzle) with a suction opening through which dirt particles are sucked from the surface to be cleaned by means of an airflow. This airflow can be generated by a fan. The airflow then carries the dirt particles from the suction opening, through a suction channel, into a dirt collection container of the cleaning robot.

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

[0004] US 2021 / 228048 A1 describes a side brush for a cleaning robot. CN 103 169 432 A describes a foldable side brush for a cleaning robot. US 2019 / 059676 A1 describes a side brush for a cleaning robot with curved support arms for bristle bundles. DE 199 19 024 A1 describes a matting brush for processing metal jewelry.

[0005] This document addresses the technical task of increasing the cleaning effect of one or more side brushes of a cleaning robot.

[0006] The problem is solved by the subject matter of each independent patent claim. Advantageous embodiments are defined in particular in the dependent patent claims, described in the following description, or illustrated in the accompanying drawing.

[0007] One aspect describes a side brush for a cleaning robot. The side brush can be designed to be positioned laterally next to the cleaning unit (especially the suction nozzle) of the cleaning robot, particularly to sweep dirt particles towards the cleaning unit.

[0008] The side brush includes a hub with a coupling element. The side brush is designed to be connected via the coupling element to a drive (e.g., an electric motor).

[0009] The side brush is connected to the motor of the cleaning robot to selectively rotate the side brush around an axis of rotation in a first direction or in an opposite second direction. The axis of rotation corresponds to the vertical axis of the cleaning robot when the side brush is mounted on the robot. In other words, the axis of rotation is essentially perpendicular to the surface being cleaned when the side brush is mounted on the robot.

[0010] The side brush has several cleaning arms, each attached to the hub and extending radially away from the hub. The cleaning arms can be arranged at different angular positions, particularly evenly spaced, around the side brush's axis of rotation. The side brush may have two or more, or three or more cleaning arms. However, a side brush typically has fewer than ten or seven cleaning arms. The cleaning arms may consist of tufts of bristles and / or one or more rubber arms.

[0011] The side brush is designed such that a tangential force acting perpendicular to the radial direction, exerted on a surface to be cleaned by the cleaning arms 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 designed such that the bending stiffness 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.

[0012] 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 on a surface to be cleaned during a rotational movement of the side brush by the cleaning arms is higher in the second direction of rotation than in the first direction of rotation; and / or that the bending stiffness of the cleaning arms is higher in the second direction of rotation than in the first direction of rotation.

[0013] This describes a side brush that exhibits different cleaning properties depending on its direction of rotation. In one direction, it provides a relatively high sweeping action, while in a second direction, it offers enhanced action for loosening dirt particles. This allows for an efficient improvement in the cleaning performance of a cleaning robot.

[0014] The individual cleaning arms extend along a respective longitudinal direction away from the hub. The individual cleaning arms can have a curved path along this longitudinal direction, with the curved path of each cleaning arm oriented towards the second direction of rotation. The curved path of the individual cleaning arms can be such that the end of the respective cleaning arm located at the hub has an orientation that deviates by no more than 10° from the radial direction; and the end of the respective cleaning arm facing away from the hub has an orientation that deviates by no more than 30° from the tangential direction.

[0015] By providing cleaning arms that have a curved shape in their unused initial state, a rotation-direction-dependent bending stiffness can be provided in a particularly efficient manner.

[0016] Each cleaning arm can have a first sub-arm and a second sub-arm, both extending along the longitudinal direction. A longitudinal gap can be arranged between the first and second sub-arms. This further enhances the effect of the rotation-direction-dependent bending stiffness.

[0017] The side brush can have one or more support elements for each individual cleaning arm, each designed to act on the respective cleaning arm at at least one point along its longitudinal direction in order to impede tangential movement of the cleaning arm. The one or more support elements for each cleaning arm can be designed such that the tangential movement of the cleaning arm is impeded more strongly in the first direction of rotation than in the second direction.

[0018] The one or more support elements allow the freely movable length of the individual cleaning arms to be changed, and in particular reduced, depending on the direction of rotation. This enables a rotation-direction-dependent bending stiffness to be provided in a particularly efficient and reliable manner.

[0019] The one or more support elements for a cleaning arm can each include a sleeve that at least partially encloses the cleaning arm along a specific length from the hub in the longitudinal direction. The bending stiffness of the cleaning arm can then be determined by the length of the sleeve.

[0020] The sleeve for a cleaning arm can be closed on the side facing the first direction of rotation and 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 its longitudinal axis on the side facing the first direction of rotation than on the side facing the second direction of rotation. This allows for a particularly efficient and reliable provision of rotation-direction-dependent bending stiffness.

[0021] The side brush can include 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 axis of rotation, so that 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 optionally be effected by an actuator of the cleaning robot. This allows for a particularly convenient and reliable provision of rotation-direction-dependent bending stiffness.

[0022] The side brush can comprise a first ring on which a support element is arranged for each cleaning arm. This support element is designed to impede the tangential movement of the cleaning arm when the side brush is rotated in the first direction. Furthermore, the side brush can comprise a second ring on which a support element is arranged for each cleaning arm. This support element is designed to impede the tangential movement of the cleaning arm when the side brush is rotated in the second direction. The first ring can have a smaller diameter (e.g., by 10% or more, or by 20% or more) than the second ring. This allows for a particularly efficient and reliable provision of rotation-direction-dependent bending stiffness.

[0023] 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 steps 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 automatically effected by an actuator of the cleaning robot. This allows for a particularly convenient and precise adjustment of the bending stiffness depending on the direction of rotation.

[0024] The individual cleaning arms may each be connected to the hub via a joint, the joint enabling a pivoting movement of the respective cleaning arm around a pivot axis that runs parallel and offset to the axis of rotation.

[0025] The joint for a cleaning arm can be designed to be, to limit the swiveling 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 swiveling 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.

[0026] In this configuration, a cleaning arm can extend further along the radial direction in the second orientation than in the first. Alternatively or additionally, the second orientation can deviate less from the radial direction than the first. This allows for a particularly efficient and reliable provision of rotation-direction-dependent bending stiffness.

[0027] According to one aspect, a cleaning robot is described for cleaning a surface (e.g., a floor). The cleaning robot can be designed to move autonomously across the surface to be cleaned. For this purpose, the cleaning robot includes a drive system designed to move the cleaning robot along a specific direction across the surface to be cleaned. The cleaning robot includes a cleaning unit designed to be moved across the surface. The cleaning unit can have a suction nozzle and, optionally, a brush roller. The cleaning unit is designed to pick up dirt particles from the surface to be cleaned.

[0028] The cleaning robot further comprises at least one side brush, designed as described in this document. The side brush may be positioned laterally to (and, if applicable, in front of) the cleaning unit with respect to the direction of movement. The cleaning robot may optionally have a side brush on both sides (i.e., to the right and left of) the cleaning unit.

[0029] 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 towards the cleaning unit from the front, particularly against 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 away from the cleaning unit from the front, particularly along the direction of movement.

[0030] When using one side brush on each side of the cleaning unit, the side brushes are preferably arranged symmetrically to each other. For the side brush on the left side, the first direction of rotation can be clockwise and the second direction of rotation counterclockwise. For the side brush on the right side, the first direction of rotation can be counterclockwise and the second direction of rotation clockwise. The coupling elements of the two side brushes can be designed differently, in particular keyed, 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.

[0031] The cleaning robot may include a control unit configured to determine whether the side brush should operate in a dirt-sweeping mode or a dirt-loosening mode. This can be determined, for example, based on user input and / or an analysis of the area to be cleaned.

[0032] The control unit can be configured to cause the side brush to rotate in the first direction when it has been determined that the side brush should operate in dirt-sweeping mode. Furthermore, the control unit can be configured to cause the side brush to rotate in the second direction when it has been determined that the side brush should operate in dirt-loosening mode.

[0033] This is a reliable way to increase the cleaning quality of a cleaning robot.

[0034] According to another aspect, a method for cleaning a surface in an area (e.g., in a room) using a cleaning robot is described, the cleaning robot being configured as described in this document. The method includes identifying a first sub-area where the dirt particles are to be swept from the surface and a second sub-area where the dirt particles are to be loosened from the surface (e.g., based on sensor data from one or more environmental sensors of the cleaning robot). Furthermore, the method includes causing the side brush of the cleaning robot to perform a rotational movement in the first direction in the first sub-area and causing the side brush of the cleaning robot to perform a rotational movement in the second direction in the second sub-area.

[0035] It should be noted that any aspects of the cleaning robot and / or the side brush for a cleaning robot described in this document and / or the method described in this document can be combined with one another in a variety of ways and / or arbitrarily. In particular, the features of the claims can be combined with one another in a variety of ways and / or arbitrarily.

[0036] The invention will now be described in more detail with reference to exemplary embodiments illustrated in the accompanying drawing. These show: Figures 1a and 1b show exemplary cleaning robots in different perspective views; Figure 1c shows exemplary components of a cleaning robot; Figures 2a to 2c show different views of a side brush with curved cleaning arms; Figures 3a to 3d show different views of a side brush with cleaning arms supported on one side; Figures 4a to 4h show different views of a side brush with support elements for the cleaning arms; Figures 5a to 5f show different views of a side brush with swiveling cleaning arms; and Figure 6 shows a flowchart of an exemplary method for cleaning an area.

[0037] As stated at the outset, this document deals with improving the cleaning quality of a cleaning device, in particular a cleaning robot. In this context, we show Fig. 1a the top 121 and Fig. 1bThe 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.

[0038] The underside 122 of the cleaning robot 100 faces the floor or area to be cleaned, such as a room, during vacuuming operation. The underside 122 of the cleaning robot 100 typically has one or more drive units 101 (typically with one or more drive wheels) that allow the cleaning robot 100 to move independently to clean different areas of a floor. Furthermore, the cleaning robot 100 may have one or more guide and / or support elements 104 (e.g., non-driven wheels) that enable stable movement of the cleaning robot 100 across the floor to be cleaned. In addition, a cleaning robot 100 typically includes one or more cleaning units 106 (in particular, suction nozzles) designed to clean the floor beneath the cleaning robot 100.

[0039] A cleaning unit 106 (in particular a suction nozzle) can have a brush roller 102 designed to rotate about an axis of rotation, the axis of rotation typically being arranged parallel to the underside 122 of the cleaning robot 100. The brush roller 102 can be used to mechanically loosen dust and / or contaminants from the floor to be cleaned, so that the dust and / or contaminants can be sucked into the suction opening 107 of the cleaning unit 106 with increased reliability.

[0040] A user interface can be arranged on the top surface 121 of the cleaning robot 100, allowing a user of the cleaning robot 100 to make control inputs. Furthermore, the cleaning robot 100 can include 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 collision sensor can be arranged on the bumper 105, configured to acquire sensor data indicating whether the cleaning robot 100 has collided with an obstacle in its direction of movement 120. Triggering the collision 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 axis, which is perpendicular to the floor, thereby changing its direction of movement 120 to avoid the obstacle.

[0041] Furthermore, a cleaning robot 100 typically has one or more environmental sensors 110 (see Fig. 1c), which are configured to acquire environmental and / or sensor data relating to the environment of the cleaning robot 100. The one or more environmental sensors 110 may include: one or more 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 may be configured to determine digital map information relating to the cleaning area 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 orient itself independently within the cleaning area (e.g., within a room) and / or to determine a route for cleaning the cleaning area.

[0042] Fig. 1cFigure 1 shows 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 collection container 150 that can be inserted into and removed from a container recess of the cleaning device 100.

[0043] The cleaning robot 100 can have one or more side brushes 140, each designed to sweep dirt particles towards the cleaning unit 106, in particular towards the suction nozzle 107. In the Figures 1a and 1bIn the illustrated example, 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. Optionally, a side brush 140 can be arranged on each side of the cleaning unit 106.

[0044] 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 rotational axis by the drive unit. Several cleaning arms 141 are arranged on the hub 142 and extend radially away from the hub 142. The rotation 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 towards the cleaning unit 106.

[0045] The cleaning arms 141 of a side brush 140 typically consist of relatively soft bristles, resulting in a particularly reliable sweeping action. However, the use of relatively soft bristles means that only relatively low tangential forces can be exerted on the surface to be cleaned, so dirt particles adhering to the surface are usually not dislodged by the rotating side brush 140.

[0046] This document describes a side brush 140 with cleaning arms 141, which are designed to exert different tangential forces 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 that is perpendicular to the radial direction of the side brush 140 (i.e., in the circumferential direction of the hub 142).

[0047] The side brush 140 can be configured to exert tangential forces with a first force value in a first direction of rotation and tangential forces with a second force value in the opposite second direction of rotation. 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 exhibit a relatively high degree of flexibility when the side brush 140 rotates in the first direction. This ensures a reliable sweeping effect. Conversely, relatively high tangential forces are exerted on the surface to be cleaned when the side brush 140 rotates in the second direction. This ensures the reliable removal of dirt particles from the surface to be cleaned.

[0048] Figs. 2a to 2cFigure 1 shows different views of a side brush 140, which has curved cleaning arms 141 extending from the hub 142. The side brush 140 can be rotated around the hub 142 in a first direction 201 and in an opposite second direction 202. In the first direction 201, the cleaning arms 141 can move forward towards the suction nozzle 107 of the cleaning robot 100. Conversely, in the second direction 202, the cleaning arms 141 can move forward away from the suction nozzle 107. The first direction 201 can be used to sweep dirt particles towards the suction nozzle 107. Conversely, the second direction 202 can be used to loosen dirt particles from the surface to be cleaned. The loosened dirt particles can then be swept towards the suction nozzle 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 towards the suction mouth 107.

[0049] The individual cleaning arms 141 are curved, such that each cleaning arm 141 has a path extending in both a radial and a tangential direction. A cleaning arm 141 has a longitudinal direction extending from its hub-side end (located at the hub 142) to its far end (facing away from the hub 142). The longitudinal direction of the cleaning arm 141 may correspond to the radial direction at its hub-side end. With increasing distance from the hub 142, the longitudinal direction of the cleaning arm 141 may increasingly align itself with the tangential direction, possibly such that the far end of the cleaning arm 141 is essentially oriented in the tangential direction.

[0050] The individual cleaning arms 141 are bent such that their ends pointing away from the first direction of rotation 201 and / or towards the second direction of rotation 202. This pre-curvature of the individual cleaning arms 141 causes the forces acting on the individual cleaning arms 141 to bend them further away from the first direction of rotation 201 when the side brush 140 rotates in the first direction of rotation 201, thus reducing the total tangential forces exerted by the cleaning arms 141 on the surface to be cleaned.

[0051] 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 is rotated 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.

[0052] A cleaning arm 141 can have several sub-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 sub-arms 211, 212. By using several sub-arms 211, 212, the bending effect (during rotation in the first direction 201) and / or the straightening effect (during rotation in the second direction 202) can be further enhanced, thereby further improving the sweeping action (during rotation in the first direction 201) and the dirt particle removal effect (during rotation in the second direction 202) of the side brush 140.

[0053] In the Figures 3a to 3dA side brush 140 is shown, which has a support element 311 for each of the individual cleaning arms 141. This support element is designed to support the respective cleaning arm 141 when the side brush 140 rotates in the second direction 202. Conversely, the respective cleaning arm 141 is essentially not supported by the support element 311 when the side brush 140 rotates in the first 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 radial length 313, whereby the rotation-direction-selective support effect of the support element 311 can be modified by the length 313.

[0054] When the side brush 140 is rotated in the first direction of rotation 201, the cleaning arms 141 are bent tangentially to the second direction of rotation 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 direction of rotation 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 to the first direction of rotation 201, thus resulting in relatively high tangential forces exerted by the individual cleaning arms 141 on the surface to be cleaned.

[0055] In the Figures 4a to 4hA side brush 140 is shown, which has one or more support elements 401, 402 for each individual cleaning arm 140. These support elements can be retracted or extended as needed. The individual support elements 401, 402 are arranged radially spaced from the hub 142. The support effect of a support element 401, 402 typically increases with increasing distance from the hub 142.

[0056] 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 generating different tangential forces on the surface to be cleaned, depending on the direction of rotation 201, 202. For each individual cleaning arm 141, a (retractable) support element 401, 402 can be provided for each of the two directions of rotation 201, 202.

[0057] The provision of a retractable support element 401, 402 makes it possible to change the bending stiffness 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 bending stiffness. Conversely, when the support element 401, 402 is extended, the cleaning arm 141 has a relatively high bending stiffness. Fig. 4f An example of a retracted support element 402 is shown, which does not support a cleaning arm 141 when the side brush 140 is rotated in the first direction of rotation 201, so that a relatively good sweeping effect can be achieved with the cleaning arm 141. 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 direction of rotation 201. In this case, the cleaning arm 141 has an enhanced effect on loosening dirt particles.

[0058] 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 allows the cleaning arm 141 to pivot between a first stop 511 and a second stop 512. The cleaning arm 141 can be positioned at the first stop 511 by rotating the side brush 140 in the first direction of rotation 201. Conversely, the cleaning arm 141 can be positioned at the second stop 512 by rotating the side brush 140 in the second direction of rotation 202.

[0059] The first stop 511 and the second stop 512 can be designed such that the longitudinal direction of the cleaning arm 141 is more strongly oriented tangentially 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 result in the tangential forces exerted by the cleaning arm 141 being 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.

[0060] 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. In particular, the side brush 140 can have increased stiffness in a second direction of rotation 202, so that dirt can be loosened from the ground 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, it can be increased as needed, for example, to reach narrow passages that are inaccessible to vehicles.

[0061] The cleaning robot 100 can be a vacuuming and / or sweeping robot, which may have an optional wet cleaning module. The cleaning robot 100 may have a brush roller 102 rotating around a horizontal axis for sweeping up relatively coarse dirt particles and / or a suction fan for vacuuming up fine dust particles. Collected dust and dirt can be stored in a collection container 150. A rotating side brush 140 may be arranged at at least one front corner of the housing of the cleaning robot 100.

[0062] In standard operation, the side brush 100 rotates at its leading edge towards the center of the cleaning robot 100; that is, 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 exhibit a comparatively low flexural rigidity. The side brush 140 appears "soft" and "flexible" and therefore has relatively good sweeping properties (even for relatively fine dust particles).

[0063] The side brush 140 can be designed such that the cleaning arms 141 have a distinctly curved shape (as exemplified in the Figures 2a to 2c(as shown). The bending occurs predominantly in the horizontal plane, so that the side brush 140 resembles a spiral when viewed along its axis of rotation. With respect to the standard direction of rotation 201 of the side brush 140, the cleaning arms 141 are bent in the opposite direction. The bending can be combined with a (section-wise) tapering of the cleaning arms 141 towards the outside. The cleaning arms 141 preferably do not have any significantly straight sections.

[0064] 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 into their predetermined curved position. There is relatively little resistance in the individual cleaning arms 141, so they bend relatively easily and thus exhibit relatively low bending stiffness in this direction of rotation 201. When rotating against the standard direction of rotation, i.e., in the second direction of rotation 202, the frictional forces act against the predetermined bending, so the individual cleaning arms 141 brace themselves against bending, resulting in increased bending stiffness of the side brush 141.

[0065] 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 exemplified in the Figures 3a to 3d(as shown). 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 varying degrees (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 on one side, so that the sleeve 311 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. The bending stiffnesses result from the material properties of the cleaning arm 141 and the unsupported length of the cleaning arm 141, depending on the direction of rotation 201, 202. The shorter the unsupported length of the cleaning arm 141, the higher the bending stiffness.

[0066] For rotation of the side brush 140 in the standard direction of rotation 201, the cleaning arms 141 are preferably only slightly or not at all supported to allow bending along their entire length. The cleaning arms 141 then have low resistance, act "softly," 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. This noticeably increases the bending stiffness.

[0067] In an extended form, the sleeve 311 for support can have a variable length 313, so that the bending stiffness can be adjusted (stepwise or continuously) even during the operation of the cleaning robot 100 (automatically) and with the same direction of rotation 202 of the side brush 140.

[0068] Alternatively or additionally, the outer support of the cleaning arms 141 can be provided by a comb (as exemplified in the Figures 4a to 4h(as shown). This comb can be circular, resembling a "toothed crown," and act, for example, on the cleaning arms 141 from above. Where the comb (especially the teeth 401, 402 of the comb) contacts the cleaning arms 141, the cleaning arms 141 are supported, thus shortening their effective length and increasing their bending stiffness. 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 or 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 act on the cleaning arms 141 from one side, can be arranged on a circular ring with a significantly different diameter than the teeth 402, which act on the cleaning arms 141 from the other side.

[0069] A change in the bending stiffness of the cleaning arms 141, while maintaining the standard direction of rotation 201 of the side brush 140, can be achieved by making the comb movable so that it can be moved towards the cleaning arms 141 as needed. For example, the comb can be designed to lower itself onto the side brush 140 from above (along the axis of rotation of the side brush 140). When the comb is retracted (above the side brush 140), the cleaning arms 141 can bend freely and thus have a "soft" action. When the comb is extended (comb teeth 401, 402 at the level of the cleaning arms 141), the comb supports the cleaning arms 141, shortens their effective length, and thus increases the bending stiffness.

[0070] Alternatively or additionally, a comb can be used whose teeth 401, 402 can be moved tangentially away from or towards the individual cleaning arms 141. If the comb teeth 401, 402 move away from the cleaning arms 141, the latter can bend more easily. If the comb teeth 401, 402 move closer to or touch the cleaning arms 141, bending becomes more difficult or is prevented, and the bending stiffness increases.

[0071] Alternatively or additionally, the individual support elements 401, 402 (especially teeth) can be designed to be moved radially. By moving the individual support elements 401, 402 along the radial direction (possibly continuously or in steps), the effective length of the individual cleaning arms 141 can be changed (continuously or in steps) in order to change the bending stiffness of the individual cleaning arms 141 (continuously or in steps).

[0072] Alternatively or additionally, different effective bending stiffnesses depending on the direction of rotation 201, 202 can be achieved by using rotary joints or flexible joint points 513 on the cleaning arms 141 and stops 511, 512 to limit the joint movement (see Figures 5a to 5fThe altered bending stiffness is based on the resistance that the cleaning arms 141 can exert at a specific angle against a tangential external force. In the standard direction of rotation 201, a cleaning arm 141 can rotate at the pivot point 513 by a certain angle before being held by the first stop 511. Depending on the angle of rotation, the cleaning arm 141 merely glides over the floor without offering or exhibiting any significant bending resistance. In the opposite direction of rotation 202, the second stop 512 can hold the cleaning arm 141 at an angle projecting almost perpendicularly from 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 exhibits increased bending stiffness.

[0073] The pivot joints or joint points 513 on the cleaning arms 141 are typically not coaxial with the axis of rotation 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 (i.e. the hub) 142 of the side brush 140, respectively.

[0074] 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 loosen caked-on dirt from the floor in places that the main brush 102 cannot reach on the other. This can be achieved by increasing the bending stiffness depending on the direction of rotation.

[0075] Different bending stiffnesses allow for different "softnesses" of the cleaning arms 141, which are reflected in altered sweeping properties that are advantageous depending on the type of dirt or particle size.

[0076] The different deflections 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, thus allowing for side brush characteristics adapted to specific situations. These different effective diameters correspond to 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).

[0077] This document describes a side brush 140 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, which can be achieved by geometric means (e.g., spiral arms) and / or mechanical means. Thus, when the direction of rotation is reversed, the side brush 140 exhibits a higher stiffness, enabling the removal of stubborn dirt.

[0078] The control unit 130 of the cleaning robot 100 can be configured to identify a specific location where dirt should be removed from the floor, based on sensor data from one or more sensors 110 (e.g., a camera) and / or navigation data (e.g., a digital map of the area to be cleaned). The one or more side brushes 140 can then be operated at the identified location in the second direction of rotation 202 to remove the dirt from the floor.

[0079] Fig. 6 shows a flowchart of a (possibly computer-implemented) procedure 600 for (spot) cleaning of an area using a cleaning robot 100, wherein the cleaning robot 100 is designed as described in this document.

[0080] Method 600 comprises identifying 601 a first sub-area of ​​the area where the dirt particles are to be swept from the surface, and a second sub-area of ​​the area where dirt particles are to be removed from the surface. This can be done based on sensor data from one or more environmental sensors 110 of the cleaning robot 100.

[0081] Method 600 further comprises causing 602 the side brush 140 of the cleaning robot 100 to perform a rotational movement in the first direction of rotation 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 direction of rotation 202 in the second sub-area. This allows both sub-areas to be cleaned with a particularly high level of quality.

[0082] Method 600 can further include causing the side brush 140 of the cleaning robot 100 to be operated in a subsequent step (following operation with a rotary movement in the second direction of rotation 202) in the second sub-area with a rotary movement in the first direction of rotation 201. This allows the previously loosened dirt to be reliably swept into the second sub-area.

[0083] To clean a specific area, the side brush 140 of the cleaning robot 100 can first be operated with a rotational movement in the second direction of rotation 202 (to loosen dirt) and subsequently (in the same area) with a rotational movement in the first direction of rotation 201. This allows for particularly thorough cleaning.

[0084] 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 and / or the side brush and / or the method described in this document. Reference symbol list

[0085] 100 Cleaning device (cleaning robot) 101 Drive unit 102 Brush roller 104 Guide and / or support element 105 Bumper 106 Cleaning unit / Suction nozzle 107 Suction mouth 110 Environmental sensor 111 Storage unit 120 Direction of movement / Longitudinal direction 121 Top 122 Bottom 123 Side wall 130 Control unit 140 Side brush 141 Cleaning arm 142 Hub (of the side brush) 150 Collection container / Dust box 201 First direction of rotation 202 Second direction of rotation 211 First section arm 212 Second section arm 213 Gap between the sections arms 311 Support element (sleeve) 313 Radial length of the support element 401 Support element 402 Support element 511 First stop 512 second stop 513 joint 600 procedure 601, 602 procedure step

Claims

1. Cleaning robot (100) for cleaning a surface, wherein the cleaning robot (100) comprises - a drive (101) that is designed to move the cleaning robot (100) along a direction of movement (120) over a surface to be cleaned; - a cleaning unit (106) that is designed to pick up dirt particles from the surface to be cleaned; and - a side brush (140), wherein - the side brush (140) comprises a hub (142) with a coupling element; - the side brush (140) is designed to be connected via the coupling element to a drive of the cleaning robot (100), in order to cause a rotational movement of the side brush (140) around an axis of rotation selectively in a first direction of rotation (201) or in an opposite second direction of rotation (202); - the axis of rotation 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 multiple cleaning arms (141) which are each attached to the hub (142) and each extend in the radial direction away from the hub (142); - the side brush (140) is designed such that a tangential force, which acts perpendicular to the radial direction and is exerted on a surface to be cleaned during a rotational movement of the side brush (140) by means of the cleaning arms (141), is higher in the second direction of rotation (202) than in the first direction of rotation (201); and - the is arranged laterally next to the cleaning unit with respect to the direction of movement (120), so that - during 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 towards the cleaning unit (106), in particular against the direction of movement (120), and - during a rotational movement of the side brush (140) in the second direction of rotation (202), the cleaning arms (141) of the side brush (140) move towards the front away from the cleaning unit (106), in particular along the direction of movement (120). wherein the cleaning robot (100) is characterised in that the cleaning robot (100) comprises a control unit (130) which is configured - to determine whether the side brush (140) is to be operated in a dirt-sweeping mode or a dirt-loosening mode; and - to cause that - the side brush (140) performs a rotational movement in the first direction of rotation (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) performs a rotational movement in the second direction of rotation (202) if it has been determined that the side brush (140) is to be operated in the dirt-loosening mode.

2. Cleaning robot (100) according to claim 1, wherein the side brush (140) is designed such that a bending stiffness of the cleaning arms (141) in the second direction of rotation (202) is higher than in the first direction of rotation (201).

3. Cleaning robot (100) 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 means of which it is caused that the tangential force exerted on a surface to be cleaned during a rotational movement of the side brush (140) by means of the cleaning arms (141) is higher in the second direction of rotation (202) than in the first direction of rotation (201).

4. Cleaning robot (100) 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) can have a curved shape along the longitudinal direction; and - the curved shape of the individual cleaning arms (141) is oriented towards the second direction of rotation (202).

5. Cleaning robot (100) according to claim 4, wherein the curved shape 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 from the radial direction by no more than 10°; and - that an end of the cleaning arm (141) facing away from the hub (142) has an orientation that deviates from the tangential direction by no more than 30°.

6. Cleaning robot (100) 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 first partial arm (211) and a second partial arm (212) which each extend 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. Cleaning robot (100) 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 side brush (140) has one or more support elements (311, 401, 402) for each of the individual cleaning arms (141), each support element being 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) towards the first direction of rotation (201) is hindered to a greater extent than towards the second direction of rotation (202).

8. Cleaning robot (100) according to claim 7, wherein the one or more support elements (311, 401, 402) for a cleaning arm (141) comprise a sleeve (311) that at least partially encloses the cleaning arm (141) along a specific length (313) starting from the hub (142) along the longitudinal direction.

9. Cleaning robot (100) 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. Cleaning robot (100) according to one of the 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. Cleaning robot (100) 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) respectively; 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 act on it.

12. Cleaning robot (100) 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) respectively, said support element being 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) respectively, said support element being 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. Cleaning robot (100) according to one of claims 7 to 12, wherein - the 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 multiple 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 automatically caused by means of an actuator of the cleaning robot (100).

14. Cleaning robot (100) according to one of the preceding claims, wherein - the individual cleaning arms (141) are each attached to the hub (142) via a joint (513) which renders possible a pivoting movement of the respective cleaning arm (141) around a pivot axis that runs parallel and offset to the axis of rotation; - the joint (513) for a cleaning arm (141) is designed - to limit the pivoting movement of the cleaning arm (141) by means of 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 means of 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 to a lesser extent from the radial direction than the first orientation.

15. Method (600) for cleaning a surface in an area by means of a cleaning robot (100), wherein the cleaning robot (100) comprises - a drive (101) that is designed to move the cleaning robot (100) along a direction of movement (120) over an area to be cleaned; - a cleaning unit (106) that is designed to pick up dirt particles from the surface to be cleaned; and - a side brush (140) wherein - the side brush (140) comprises a hub (142) with a coupling element; - the side brush (140) is designed to be connected via the coupling element to a drive of the cleaning robot (100), in order to cause a rotational movement of the side brush (140) around an axis of rotation selectively in a first direction of rotation (201) or in an opposite second direction of rotation (202); - the axis of rotation 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 multiple cleaning arms (141) which are each attached to the hub (142) and each extend in the radial direction away from the hub (142); - the side brush (140) is designed such that a tangential force, which acts perpendicular to the radial direction and is exerted on a surface to be cleaned during a rotational movement of the side brush (140) by means of the cleaning arms (141), is higher in the second direction of rotation (202) than in the first direction of rotation (201); - the is arranged laterally next to the cleaning unit (106) with respect to the direction of movement (120), so that - during 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 towards the cleaning unit (106), in particular against the direction of movement (120); and - during a rotational movement of the side brush (140) in the second direction of rotation (202), the cleaning arms (141) of the side brush (140) move towards the front away from the cleaning unit (106), in particular along the direction of movement (120). 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 loosened from the surface; and - causing (602) that - the side brush (140) of the cleaning robot (100) performs a rotational movement in the first direction of rotation (201) in the first partial area; and - the side brush (140) of the cleaning robot (100) performs a rotational movement in the second direction of rotation (202) in the second partial area.

16. Side brush (140) for a cleaning robot (100) according to one of claims 1-14, wherein - the side brush (140) comprises a hub (142) with a coupling element; - the side brush (140) is designed to be connected via the coupling element to a drive of the cleaning robot (100), in order to cause a rotational movement of the side brush (140) around an axis of rotation selectively in a first direction of rotation (201) or in an opposite second direction of rotation (202); - the axis of rotation 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 multiple cleaning arms (141) which are each attached to the hub (142) and each extend in the radial direction away from the hub (142); - the side brush (140) is designed such that a tangential force, which acts perpendicular to the radial direction and is exerted on a surface to be cleaned during a rotational movement of the side brush (140) by means of the cleaning arms (141), is higher in the second direction of rotation (202) than in the first direction of rotation (201); - the individual cleaning arms (141) extend along a respective longitudinal direction away from the hub (142); - the side brush (140) has one or more support elements (311, 401, 402) for each of the individual cleaning arms (141) respectively, each support element being 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; - 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) towards the first direction of rotation (201) is hindered to a greater extent than towards the second direction of rotation (202); and the side brush (140) is characterised in that - the cleaning arms (141) are arranged at different angular positions, in particular evenly distributed, around the axis of rotation of the side brush (140); and - the side brush (140) comprises a ring on which at least one support element (401, 402) is arranged for each cleaning arm (141) respectively; 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 act on it; and / or the side brush (140) is characterised in that - the side brush (140) comprises a first ring on which a support element (402) is arranged for each cleaning arm (141) respectively, said support element being 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); and - the side brush comprises a second ring on which a support element (401) is arranged for each cleaning arm (141) respectively, said support element being 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.

17. Side brush (140) for a cleaning robot (100) according to one of claims 1-14, wherein - the side brush (140) comprises a hub (142) with a coupling element; - the side brush (140) is designed to be connected via the coupling element to a drive of the cleaning robot (100), in order to cause a rotational movement of the side brush (140) around an axis of rotation selectively in a first direction of rotation (201) or in an opposite second direction of rotation (202); - the axis of rotation 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 multiple cleaning arms (141) which are each attached to the hub (142) and each extend in the radial direction away from the hub (142); - the side brush (140) is designed such that a tangential force, which acts perpendicular to the radial direction and is exerted on a surface to be cleaned during a rotational movement of the side brush (140) by means of the cleaning arms (141), is higher in the second direction of rotation (202) than in the first direction of rotation (201); - the individual cleaning arms (141) extend along a respective longitudinal direction away from the hub (142); - the side brush (140) has one or more support elements (311, 401, 402) for each of the individual cleaning arms (141), each support element being 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; - 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) towards the first direction of rotation (201) is hindered to a greater extent than towards the second direction of rotation (202); and the side brush (140) is characterised in that - 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 multiple stages or continuously; and - the side brush (140) is designed such that the change in the tangential distance of the support element (311, 401, 402) to the cleaning arm (141) can be caused automatically by means of an actuator of the cleaning robot (100).

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