Self-propelled floor treatment device

Abstract

The invention relates to a self-propelled floor treatment device (1), in particular to a cleaning robot, with a floor treatment element (2), at least two motorized wheels (3, 4) and a detection device for detecting a floor type of a surface to be treated. In order to easily achieve an optimal detection of the floor type, it is proposed that the detection device have a frictional resistance element (6), which contacts the surface during a movement in such a way that a resultant force outside of a reference axis (7) acts on the floor treatment device (1), wherein the reference axis (7) is oriented parallel to a main direction of movement (8) of the floor treatment device (1) prescribed by the orientation of the wheels (3, 4), and is aligned centrally between the wheels (3, 4) in relation to a direction perpendicular to the reference axis (7). Further proposed is a method for operating a self-propelled floor treatment device (1).

Claims

1. A self-propelled floor treatment device (1), in particular a cleaning robot, with a floor treatment element (2), at least two motorized wheels (3, 4) and a detection device for detecting a floor type of a surface to be treated, wherein the detection device has a frictional resistance element (6), which contacts the surface during a movement in such a way that a resultant force acts outside of a reference axis (7) on the floor treatment device (1), wherein the frictional resistance element (6) is arranged non-symmetrically to the reference axis (7) defined by a position of the wheels (3, 4) on the floor treatment device (1), and wherein the reference axis (7) is oriented parallel to a main direction of movement (8) of the floor treatment device (1) prescribed by the orientation of the wheels (3, 4), and aligned centrally between the wheels (3, 4) in relation to a direction perpendicular to the reference axis (7), and wherein the frictional resistance element is arranged such that the frictional resistance element (6) is exposed to the force, which because the frictional resistance is not centrally arranged relative to the wheels causes the floor treatment device to drift on the surface.

2. The floor treatment device (1) according to claim 1, wherein the frictional resistance element (6) is a treatment element (1) for treating the surface to be treated, in particular a cleaning roller that rotates perpendicular to the reference axis (7).

3. The floor treatment device (1) according to claim 1 wherein the frictional resistance element (6) is arranged perpendicular to the reference axis (7), and has a larger length on one side of the reference axis (7) than on the opposite side of the reference axis (7).

4. The floor treatment device (1) according to claim 1, comprising a controller and evaluator (5), which is set up to detect the floor type by comparing the speeds of the wheels (3, 4) at the same driving force and comparing a determined difference in speed with floor type-dependent reference differences.

5. The floor treatment device (1) according to claim 1, wherein the detection device has an ammeter allocated to a drive motor of the frictional resistance element (6), wherein a controller and evaluator (5) of the floor treatment device (1) is set up to compare a current received by the drive motor with floor type-dependent reference currents.

6. The floor treatment device (1) according to claim 1, wherein the detection device has an optical reflection measuring device (9) with a light source and a light receiver, wherein a light emission direction of the light source is essentially directed toward the ground plane spanned by the wheels (3, 4).

7. The floor treatment device (1) according to claim 6, wherein the reflection measuring device (9) is a distance measuring device, in particular a distance measuring device designed to detect precipices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail below based on exemplary embodiments. Shown on:

(2) FIG. 1 is a perspective, external view of a floor treatment device according to the invention,

(3) FIG. 2 is a bottom view of the floor treatment device,

(4) FIG. 3 is a drifting movement of the floor treatment device.

DESCRIPTION OF THE EMBODIMENTS

(5) FIG. 1 shows a floor treatment device 1 according to the invention, which is here designed as a vacuuming robot. The floor treatment device 1 is positioned on a surface, e.g., here a wooden floorboard. The floor treatment device 1 is self-propelled, and has a navigation and self-localization device, which allows an orientation inside of premises. The floor treatment device 1 has two wheels 3, 4 (see FIG. 2) along with a floor treatment element 2, which here is designed like a brush roller. The floor treatment device 1 is supported against the surface to be cleaned by the two wheels 3, 4 on the one hand, and with a contact surface 13 of the floor treatment element 2 on the other, wherein both the wheels 3, 4 for moving the floor treatment device 1 and the floor treatment element 2 for cleaning purposes are motorized. The floor treatment device 1 has a main direction of movement 8, which is prescribed by the rotational plane of the wheels 3, 4. The floor treatment element 2 is arranged perpendicular to this main direction of movement 8, wherein the floor treatment element 2 rotates around a rotational axis 10.

(6) The floor treatment device 1 further has an also motorized side brush 12, which is suitable in particular for cleaning room corners and room boundaries. In addition, the floor treatment device 1 has a distance measuring device 11, e.g., which is here designed as a triangulation measuring device arranged inside of the floor treatment device 1, and can measure distances from obstacles, preferably in an angular range of 360 degrees. The distance measuring device 11 is part of the navigation and self-localization device.

(7) FIG. 2 shows the floor treatment device 1 as viewed from below. Further evident here are two reflection measuring devices 9, which serve to measure the distance from a surface arranged underneath the floor treatment device 1. In particular, these reflection measuring devices 9 are suitable for preventing the floor treatment device 1 from falling into a precipice, for example on steps. The reflection measuring device 9 has a light source and a light receiver (neither shown), wherein the light source directs a beam of light onto a surface to be cleaned. This beam of light is first at least partially reflected or scattered on the surface, wherein a component usually gets back to the light receiver of the reflection measuring device 9 and can be evaluated for distance measurement purposes. The reflection measuring device 9 is further used to determine the floor type of the surface to be cleaned, since the floor type can also be inferred based on the reflectance of the surface, e.g., because a carpeted floor reflects less than a hard floor, such as a tile floor or wooden floor.

(8) The floor treatment element 2, i.e., the bristle roller, is here simultaneously a frictional resistance element 6, which touches the surface to be treated with its contact surface 13 with the floor treatment device 1 set up on the surface to be cleaned. Depending on the floor type of the surface, e.g., carpeted floor or hard floor, the frictional resistance element 6 exerts more or less of a frictional force on the surface as the floor treatment device 1 moves. The frictional resistance element 6 is unsymmetrically arranged in relation to a reference axis of the floor treatment device 1. The reference axis 7 is oriented parallel to the main direction of movement 8 of the floor treatment device 1, and also centrally placed between the two wheels 3, 4 in relation to a direction perpendicular to the reference axis 7. As a result, the frictional resistance element 6 has more of an overhang and a larger portion of the contact surface 13 on one side of the reference axis 7 than on the opposite side. As the floor treatment device 1 moves over the surface, a force imbalance comes about in relation to the two half-sides of the floor treatment device 1, since a significantly higher frictional force acts on the half side of the floor treatment device having the wheel 3 than on the opposite side having the wheel 4. As a result, the floor treatment device 1 exits the main direction of movement 8 pursued previously toward the side having the larger portion of contact surface 13 to the surface to be treated. Here, this is the half side of the floor treatment device 1 on which the wheel 3 is arranged.

(9) FIG. 3 shows how the floor treatment device drifts during a forward movement, which is caused by the unsymmetrical arrangement of the frictional resistance element 6. The floor treatment device 1 coming from the right and traveling in a main direction of movement 8 in the illustration according to FIG. 3 is pivoted to the left by the frictional force acting on the frictional resistance element 6, and thus exits the preceding main direction of movement 8. Exposure to the frictional force leads to a difference in speed of the driven wheels 3, 4, wherein the wheel 3 here has a lower resultant speed on the half side of the floor treatment device 1 with the higher portion of the frictional resistance element 6 than the other wheel 4. This difference in speed is calculated by a controller and evaluator 5 (see FIG. 2) of the floor treatment device 1, and compared with reference differences characteristic for specific floor types. For example, the reference differences can be stored in a memory of the floor treatment device 1, which the controller and evaluator 5 can access. In addition, it is also possible for the reference differences to be stored on a memory of an external server, and for the controller and evaluator 5 to access them through wireless communication. For example, the reference differences can also be indicated in the form of difference ranges, so that a correlation is detected if the calculated difference in speed falls within a specific difference range. Given a correlation, the floor type of the surface to be cleaned can be reliably determined.

(10) Depending on whether the floor type is known, a targeted treatment of the surface to be treated can then be controlled. In particular, it is possible to specifically adjust the power of a suction fan of the floor treatment device 1, a speed of the floor treatment element 2 or the like. In addition, it is also possible to incorporate information about the position of specific floor types, e.g., carpeted floors, into an area map, for example which is accessed by the navigation system of the floor treatment device 1.

(11) In order to even further increase the reliability of floor type determination, the supplemental use of additional methods for floor type determination can be provided. For example, the reflection measuring device 9 described above can be used for this purpose, which evaluates a reflection of the currently traversed surface and allocates it to known floor types. In addition, it is also possible to measure and evaluate the current consumption of a drive motor of the floor treatment element 2 and/or the side brush 12.

(12) Even though the invention was here described in relation to a floor treatment device 1 designed as a vacuuming robot, the floor treatment device 1 can basically also be designed as a wiping robot, combined vacuuming-wiping device or the like. It is also possible that the floor treatment involve not just cleaning a surface, but other treatment tasks, such as polishing, grinding, lubricating and the like.

REFERENCE LIST

(13) 1 Floor treatment device 2 Floor treatment element 3 Wheel 4 Wheel 5 Controller and evaluator 6 Frictional resistance element 7 Reference axis 8 Main direction of movement 9 Reflection measuring device 10 Rotational axis 11 Distance measuring device 12 Side brush 13 Contact surface