METHOD FOR OPERATING A MOBILE SELF-PROPELLED APPLIANCE AND MOBILE SELF-PROPELLED APPLIANCE OPERATED ACCORDING TO THE METHOD

Abstract

A method for operating a mobile self-propelled appliance, in particular a floor cleaning appliance such as a robot vacuum cleaner and/or robot sweeper and/or robot mopping appliance, includes detecting at least one obstacle in a floor processing area, cleaning a surrounding area of the obstacle by using at least two straight driving maneuvers at the obstacle from different directions, and basing the number and direction of the straight driving maneuvers on a size and/or shape of the obstacle. A mobile self-propelled appliance which is configured to implement the method is also provided.

Claims

1. A method for operating a mobile self-propelled appliance or at least one of a floor cleaning appliance, a robot vacuum cleaner, a robot sweeper or a robot mopping appliance, the method comprising the following steps: detecting at least one obstacle in a floor processing area; cleaning an area surrounding the obstacle by carrying out at least two straight driving maneuvers at the obstacle from different directions; and basing a number and direction of the straight driving maneuvers on at least one of a size or a shape of the obstacle.

2. The method according to claim 1, which further comprises further basing the number of straight driving maneuvers on at least one of an operating range of cleaning elements of the appliance or a predetermined minimum distance between the appliance and the obstacle.

3. The method according to claim 2, which further comprises determining a planning of the driving maneuvers by using an outer circle enveloping a contour of the obstacle and an inner circle lying on an inside of the contour of the obstacle.

4. The method according to claim 3, which further comprises performing the straight driving maneuvers if a radius of the outer circle does not exceed a predefined threshold value.

5. The method according to claim 3, which further comprises determining an overlapping circle segment based on an intersection of the operating range of the cleaning elements with the inner circle.

6. The method according to claim 5, which further comprises determining a center point angle based on the overlapping circle segment.

7. The method according to claim 6, which further comprises determining the number of driving maneuvers by using the center point angle.

8. The method according to claim 6, which further comprises performing at least one of: two driving maneuvers when the center point angle is greater than or equal to 180?; three driving maneuvers when the center point angle is between 120? and 180? inclusive; or four driving maneuvers when the center point angle is between 90? and 120? inclusive.

9. A mobile self-propelled appliance operated according to claim 1, the mobile self-propelled appliance comprising a computing unit configured to calculate the number of straight driving maneuvers based on at least one of a size or a shape of the obstacle.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0051] FIG. 1 is a diagrammatic, top-plan view of an exemplary embodiment of a mobile self-propelled appliance according to the prior art during chair leg cleaning;

[0052] FIG. 2A is a diagrammatic, top-plan view of an exemplary embodiment of a mobile self-propelled appliance in accordance with the invention during chair leg cleaning;

[0053] FIG. 2B is a diagrammatic, bottom-plan view of an exemplary embodiment of a mobile self-propelled appliance in accordance with the invention;

[0054] FIGS. 3A-3C are respective diagrammatic, top-plan views of obstacles to define the outer circle and the inner circle;

[0055] FIGS. 4A-5B are respective diagrammatic, top-plan views for defining the outer circle, the inner circle, the range, the minimum distance, the center point angle, and the height of the overlapping circle segment; and

[0056] FIG. 6 is a flowchart relating to an exemplary embodiment of an operating method in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0057] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a mobile, self-propelled appliance, in particular a robot vacuum cleaner 1, which includes a suction mouth 2, drive wheels 3a, 3b and a cleaning element 4, in particular a side brush. The side brush is disposed at a front right-hand side corner of an appliance housing of the robot vacuum cleaner 1, and renders it possible for the robot vacuum cleaner to perform improved edge and corner cleaning.

[0058] In order to clean small obstacles 5, such as for example chair or table legs, it is conventionally provided that the robot vacuum cleaner 1 drives around the leg that is to be cleaned with the side brush on the leg. However, due to the size of the suction mouth, the positioning of the side brush, and the shape of the appliance housing, there is the risk that a surrounding area 6 of the obstacle 5 or a circular edge around the obstacle 5. remains uncleaned.

[0059] In order to render it possible to clean to the edge around smaller obstacles, in accordance with the invention straight driving maneuvers 9 from different directions are used, as shown, for example, in FIG. 2A. The number of straight passes required for this can be derived inter alia from the size and shape of the obstacle 5. In accordance with the invention, an improved edge cleaning is realized by an optimization of the driving strategy of the robot vacuum cleaner 1.

[0060] The robot vacuum cleaner has a cleaning element 4 at one of its front corners, for example a rotating side brush, a fixed bristle strip or a cleaning cloth, which projects beyond the contour of the robot vacuum cleaner, as is illustrated in FIGS. 2A, 2B. The housing shape preferably has a D-shape. Alternatively, the robot vacuum cleaner can have a round shape. Through the use of its drive wheels 3a, 3b, a castor wheel 7 and a control facility, the robot vacuum cleaner is able to travel straight paths in any direction on the floor that is to be cleaned. In order to detect, scan and determine the shape and size of obstacles in the floor processing area, a lidar sensor (not illustrated) is used, which is disposed on a rear area of the appliance housing and projects beyond this appliance housing. The necessary number of straight driving maneuvers 9, in particular passes, can be determined based on the derived shape and size of the detected obstacle 5 and based on an operating range 8 of the cleaning element 4 and a desired minimum distance between the robot vacuum cleaner and the obstacle 5 during the drive past. In particular, the cleaning around the obstacle 5 can be planned in advance.

[0061] In order to plan the straight driving maneuvers, in a first step, a smallest outer circle 10, which touches the contour of the obstacle 5 at least at two outer corner points, and an inner circle 11, that is concentrically disposed in the center of the outer circle 10 and that lies against the innermost edge, are determined. In FIGS. 3A, 3B, 3C, examples are illustrated of different obstacles 5 having different contours 12. For the different obstacles 5, in particular in each case the outer circle 10, which lies against the outside or envelops the obstacle, and the inner circle 11 that lies against the inside are determined.

[0062] The straight driving maneuver in accordance with the invention is used in particular only in the case of obstacles 5 that are classified as small. Whether an obstacle is to be classified as small can be determined via checking the outer circle 10. If the radius r.sub.A of the outer circle 10 exceeds a predefined threshold value r.sub.G, the robot vacuum cleaner 1 with its protruding cleaning element 4 cleans to the edge, even in the case of driving normally around the obstacle 5, by using edge tracking along the contour 12. In this case, the straight driving maneuver in accordance with the invention is not necessary. Obstacles which have a radius r.sub.A of the outer circle 10 that falls below the predefined threshold value r.sub.G cannot be cleaned to the edge by edge tracking maneuvers. In this case, the straight driving maneuver in accordance with the invention is used so as to drive around the obstacle 5 in order to clean to the edge.

[0063] In order to ensure that cleaning to the edge and driving past the obstacle 5 from any direction at the minimum distance are possible, the difference between the outer circle radius r.sub.A and the inner circle radius r.sub.I (r.sub.A?r.sub.I) is compared with the effective operating range of the cleaning element (operating range ?.sub.R-minimum distance as). The more similar the contour 12 of the obstacle 5 is to a circle, the smaller the difference in the circular radii (r.sub.A?r.sub.I) and the easier it is to reach all obstacle edges during cleaning while passing. The operating range of the cleaning element and the minimum distance from the robot vacuum cleaner to the obstacle as well as the circular radii, are illustrated in FIGS. 4A and 4B.

[0064] In FIGS. 5A, 5B, the check as to whether an intersection or an overlapping circle segment 13 results between the range ?.sub.R and the inner circle 11 is shown geometrically, whereby it is possible to make a statement as to whether the obstacle 5 can be cleaned to the edge by driving past from any direction. The following applies in particular: [0065] (?.sub.R??.sub.S)?(r.sub.A?r.sub.I)>h.sub.min: Obstacle 5 can be cleaned to the edge by any passing; [0066] (?.sub.R??.sub.S)?(r.sub.A?r.sub.I) h.sub.min: Obstacle 5 cannot be cleaned to the edge by any passing; [0067] wherein h.sub.min determines a minimum height of the overlapping circle segment 13 between the inner circle 11 and the area that is swept by the cleaning element. The determination of the minimum height of the overlapping circle segment h.sub.min prevents too many driving maneuvers from being performed around the obstacle 5, and is determined from the generally maximum permitted number of driving maneuvers and the current inner circle radius r.sub.I.

[0068] The overlapping of the range ?.sub.R of the cleaning element and the inner circle 11 leads to an overlapping circle segment 13, which is defined by its height h and the center point angle ? (see FIG. 5B).

[0069] In particular, the following applies for h.sub.min:

h.sub.min=r.sub.I*(1?cos(?.sub.min/2)) [0070] with minimum center point angle ?.sub.min at the center point 14 of the overlapping circle segment 13:

?.sub.min=(2*?)/N.sub.max, [0071] wherein N.sub.max is the maximum permitted number of passes. If it is ensured that there is a sufficient overlapping segment 13 between the operating range ?.sub.R of the cleaning element and the inner circle 11, it is thus possible to calculate how many straight driving maneuvers are necessary at the obstacle 5 in order to ensure cleaning to the edge. For this purpose, in a first step, the actual height h of the overlapping circle segment 13 of inner circle 11 and the range line ?.sub.R is calculated and subsequently the resulting center point angle ? is calculated:

h=(?.sub.R??.sub.S)?(r.sub.A?r.sub.I);

?=2*ar cos(1?(h/r.sub.I)).

[0072] The number N of driving maneuvers can be determined by using the center point angle ?, in that:

N=360?/? [0073] is rounded up to the nearest integer greater than or equal to N. A difference angle ?.sub.diff between adjacent driving maneuvers in this case is:

?.sub.diff=360?/N.

[0074] If there is not a sufficient overlapping circle segment 13 between the cleaning element and the inner circle 11, which means (?.sub.R??.sub.S)?(r.sub.A?r.sub.I) h.sub.min, it is thus not possible to clean the obstacle 5 to the edge using the existing cleaning element and using straight driving maneuvers. Special movement maneuvers of the appliance are necessary in this case, for example, in order to enter into concave formations of the contour of the obstacle 5 or to position the cleaning element there in a targeted manner.

[0075] FIG. 6 illustrates a flowchart of an operating method for cleaning an obstacle to the edge. A simplified method is shown therein (on the left-hand side in the diagram), in which randomly aligned, straight passes are performed. Complex calculations are necessary on the paths shown on the right-hand side, which are oriented in detail to the shape and orientation of the obstacle.

[0076] In the first step 20, the obstacle that is to be driven around is scanned or detected in particular from several directions using the lidar sensor of the robot vacuum cleaner. The outer circle of the obstacle can be determined in step 21 using the scanned values.

[0077] If the radius of the outer circle r.sub.A falls below a predefined threshold value r.sub.G (r.sub.A<r.sub.G) in this case, the inner circle and its inner circle radius r.sub.I are determined (step 22a). If (?.sub.R??.sub.S)?(r.sub.A?r.sub.I)>h.sub.min, the center point angle ? of the overlapping circle segment is determined (step 23a). The number N of straight driving maneuvers and the difference angle are then determined in step 24a. Finally, the travel path or the travel trajectories of the robot vacuum cleaner can be planned for the cleaning of obstacles in the vicinity (step 25).

[0078] If, after step 21, the radius of the outer circle r.sub.A exceeds the predefined threshold value r.sub.G (r.sub.A r.sub.G), the cleaning element of the robot vacuum cleaner can clean to the edge during normal edge tracking travel along the contour of the obstacle (step 22b). The travel path or the travel trajectories of the robot vacuum cleaner for cleaning in the vicinity of the obstacle can be planned without further calculation (step 25).

[0079] If after step 22a (?.sub.R??.sub.S)?(r.sub.A?r.sub.I) h.sub.min, the main axes of the obstacle are determined (step 23b). If the extent along a second main axis corresponds to approximately r.sub.I, the cleaning is performed parallel to the main axes (step 24b), and the travel path or the travel trajectories of the robot vacuum cleaner are planned accordingly. If, conversely, the extent along the second main axis is >>r.sub.I, a separate treatment is necessary (step 24c) in order to be able to plan the travel path or the travel trajectories of the robot vacuum cleaner (step 25).

[0080] Any steps 20-25 are performed or determined automatically in this case by the device after the obstacle has been detected. Advantageously, user intervention is not necessary. The device independently determines which cleaning of the surrounding area it performs on the basis of the determined or detected values.