METHOD FOR OPERATING A MOBILE, SELF-PROPELLED DEVICE

Description

[0001] The invention relates to a method for operating a mobile, self-propelled device, in particular a floor cleaning device, such as a vacuum and / or sweeping robot, which is intended, among other things, for cleaning an environmental area of ​​obstacles, as well as to a mobile, self-propelled device which is operated according to such a method.

[0002] Mobile, self-driving devices such as robot vacuums are designed to autonomously clean as entire a floor area as possible. In particular, robot vacuums are designed to relieve their users of the task of regularly removing dust and dirt from the floor. This includes cleaning areas close to walls and areas around smaller obstacles, such as chair and table legs, as thoroughly and as close to the obstacle as possible.

[0003] Robot vacuums often have a side brush for cleaning. This allows the robot vacuum to clean close to walls and corners, as the robot's suction nozzle usually doesn't reach the edge of the robot's housing. The side brush is used, especially on round robot vacuums, to compensate for the relatively small suction nozzle. A side brush is well-suited for cleaning along straight wall sections. However, when avoiding smaller obstacles or objects, the side brushes can disadvantageously leave an uncleaned area or edge due to their positioning.

[0004] Some robot vacuums have a D-shaped base body. D-shaped robots, additionally equipped with a side brush, are generally very good at cleaning along walls and in corners. With D-shaped robots, the side brush can be positioned closer to the edge of the robot's contour, based on the front corners, which can improve the cleaning of straight wall sections. However, when circling around smaller obstacles, larger uncleaned areas are revealed than with round robots.

[0005] For improved edge and corner cleaning, robot vacuum cleaners are commonly equipped with an additional, separate suction channel. While the valve-switchable connection to the blower can deliver high suction power right into the corner of a room, this barely reduces the number of uncleaned areas when circling around smaller obstacles.

[0006] The publications EP 1 935 308 B1 and DE 10 2007 060 750 A1 describe pivoting brushes designed for cleaning edges along walls and in corners, and can also enable cleaning close to obstacles with appropriate maneuvers. However, the design of a pivoting or foldable unit entails increased mechanical complexity. Furthermore, the necessary, no less complex maneuvers can significantly increase the overall cleaning time.

[0007] The publications WO 2018 196 203 A1 and WO 2018 196 204 A1 describe special cleaning assemblies for chair legs. These enclose the leg and clean it all around, almost edge-to-edge. This concept can also be applied to other small objects, but its implementation involves increased mechanical complexity and is only suitable for objects with a specific diameter or a certain size and shape.

[0008] The publications WO 2022 / 092571 A1, CN 111 513 626 A, CN 106 974 593 A and CN 101 923 351 B describe driving behavior of cleaning robots on obstacles, which leads to improved floor cleaning on these obstacles.

[0009] The object of the invention is to provide a method for operating a mobile, self-propelled device in which the surrounding areas around, in particular, small obstacles and / or objects can be cleaned as seamlessly as possible using straight-line driving maneuvers.

[0010] This object is achieved by a method for operating a mobile, self-propelled device having the features of claim 1 and by a mobile, self-propelled device having the features of claim 7. Advantageous embodiments and further developments are the subject of the subclaims.

[0011] According to the invention, a method for operating a mobile, self-propelled device, in particular a floor cleaning device such as a vacuum and / or sweeping and / or wiping robot, comprises the following method steps: Detecting at least one obstacle in a soil cultivation area, cleaning an area surrounding the obstacle by at least two straight-line driving maneuvers on the obstacle from different directions, wherein the number and direction of the straight-line driving maneuvers are based on a size and / or shape of the obstacle, and wherein a planning of the driving maneuvers is determined by means of an outer circle enveloping a contour of the obstacle and an inner circle lying on the inside of the contour of the obstacle, characterized in that the straight-line driving maneuvers are carried out if a radius of the outer circle does not exceed a predefined threshold value.

[0012] According to the invention, a method is provided for reducing inaccessible areas, particularly around small obstacles, based on an optimization of the device's travel strategy. By appropriately planning the device's travel paths, complex mechanical assemblies can be advantageously eliminated. The method can advantageously be carried out independently of the shape and orientation of the obstacles or objects.

[0013] Edge-to-edge cleaning around obstacles is achieved by moving in a straight line along or past the obstacle. The number of times the device moves along the obstacle from different directions is determined, among other things, by the size and shape of the obstacle.

[0014] The device intended for this operating method preferably has a cleaning element that protrudes laterally beyond its contour. This can be, for example, a rotating side brush, fixed bristle strips, or a cleaning cloth. The device housing can be D-shaped or round, for example. With its drives and control unit, the device is preferably capable of traveling in straight paths across the floor in any direction.

[0015] A mobile, self-propelled device is specifically understood to be a floor cleaning device that autonomously cleans floors, for example, in a household. This includes, among others, vacuuming and / or sweeping and / or mopping robots, such as robot vacuum cleaners. These devices preferably operate without, or with as little as possible, user intervention during operation (cleaning mode). For example, the device automatically moves to a specified room to clean the floor according to a predefined and programmed process strategy.

[0016] In order to take any specific environmental characteristics into account, an exploratory drive with the mobile, self-propelled device is preferably carried out. An exploratory drive is understood to be a reconnaissance drive suitable for checking the area of ​​land to be worked for obstacles, spatial layout, and the like. The goal of an exploratory drive is, in particular, to be able to assess and / or represent the conditions of the soil cultivation area to be worked.

[0017] After the exploratory drive, the mobile, self-driving device is familiar with its surroundings and can communicate this information to the user in the form of a map, for example, in an app (e.g., a cleaning app) on a mobile device. The map can provide the user with the opportunity to interact with the mobile, self-driving device. The user can advantageously view information in the map and change and / or adapt it as needed.

[0018] An environmental map is understood to mean any map suitable for depicting the surroundings of the tillage area, including all its obstacles and objects. For example, the environmental map shows a sketch of the tillage area, including the furniture and walls within it.

[0019] The environmental map with the obstacles is preferably displayed in the app on a portable additional device. This serves, in particular, to visualize a possible interaction for the user. In this context, an additional device is understood to mean any device that is portable for a user, that is located outside the mobile, self-driving device, in particular, that is external and / or separate from the mobile, self-driving device, and that is suitable for displaying, providing, transmitting, and / or transmitting data, such as a cell phone, a smartphone, a tablet, and / or a computer or laptop.

[0020] The app, in particular a cleaning app, is installed on the portable attachment. This app serves to communicate between the mobile, self-propelled device and the attachment and, in particular, enables visualization of the floor cleaning area, i.e., the living space or apartment or living area to be cleaned. The app preferably shows the user the area to be cleaned as a map of the surrounding area.

[0021] Process steps are defined as steps that can be performed consecutively and that affect the driving behavior of the device. These steps can be performed directly one after the other or include intermediate steps.

[0022] Obstacles include, in particular, any objects located in the soil processing area, such as furniture, equipment, clothing, toys, pet supplies, and the like. The obstacles are detected by the device, for example, using at least one sensor, preferably a lidar sensor, and / or a collision sensor, such as a bumper.

[0023] The surrounding area of ​​an obstacle is understood to mean, in particular, the area that encloses or directly surrounds the obstacle, and in particular, adjoins it. The surrounding area extends, in particular, completely around the obstacle, for example, within a 360° radius.

[0024] A straight-line maneuver is defined as a smooth, curve-free movement of the device, particularly along a straight path. Turns, cornering, reversing, or driving on a circular path are generally not included.

[0025] Different directions are understood to mean, in particular, movements of the device along the obstacle from different directions in space or on the floor. The device's movements preferably do not run parallel to each other, but at least have an intersection at their extension. Movements of the device in opposite directions are also considered to be movements from different directions.

[0026] The size of an obstacle refers specifically to its cross-sectional size, i.e., the section through the obstacle in a plane parallel to the ground. The height of the obstacle is not taken into account. The shape of an obstacle refers specifically to its contour in a plane parallel to the ground. To determine the number of maneuvers required, the device's sensor detects the size and shape of the obstacle to be avoided. Based on the detected dimensions, the device then calculates the minimum number of straight-line maneuvers.

[0027] In an advantageous embodiment, the number of straight-line maneuvers is further based on the range of the device's cleaning elements and / or a predetermined minimum distance between the device and the obstacle. The required number of passes is therefore determined by the range of the cleaning element, e.g., the side brush, a predefined minimum distance between the device and the obstacle during the pass, and the shape and size of the obstacle. This allows for targeted planning of the cleaning run around the obstacle. The geometry of the device is taken into account during the planning and is therefore known. The obstacle is recognized and detected or scanned during the exploration run or the cleaning run using suitable sensors such as a lidar sensor, a camera, and / or a distance sensor.

[0028] According to the invention, the planning of the driving maneuvers is determined using an outer circle enclosing the contour of the obstacle and an inner circle adjacent to the contour of the obstacle. To plan the drive-bys, the smallest enclosing outer circle or circumcircle touching the contour of the obstacle at at least two outer corners is determined, as well as an inner circle or incircle arranged concentrically in the center of the outer circle and adjacent to the innermost edge. The number of straight-line driving maneuvers and the driving plan are then determined based on the determined circles.

[0029] According to the invention, the straight-line driving maneuvers are carried out if the radius of the outer circle does not exceed a predefined threshold. In particular, the driving maneuvers are only carried out for small obstacles, since with large obstacles, edge-to-edge cleaning is possible without special driving maneuvers. Whether an obstacle is to be classified as small can be determined by checking the outer circle. If its radius r A exceeds the threshold r G , it can be assumed that the device, with its protruding cleaning element, can achieve edge-to-edge cleaning even when circling the obstacle normally using edge tracking along the contour. Obstacles whose outer circle radius r A is smaller than the threshold r G cannot be cleaned edge-to-edge using edge tracking maneuvers and are therefore avoided using the inventive straight-line driving maneuvers.

[0030] If you compare the difference between the radii of the outer circle and the inner circle (r A - r I ) with the effective range of the cleaning element (range a R - minimum or safety distance a S ), you can tell whether it is possible to drive past the obstacle from any direction at the minimum distance and clean it completely. The more the contour of the obstacle resembles a circle, the smaller the difference between the circle radii (r A - r I ) and the easier it is to reach all edges of the obstacle when cleaning as it drives past. From a geometric point of view, a line of the minimum distance is drawn on the outer circle to check whether a parallel line at a distance corresponding to the range of the cleaning element intersects the inner circle.

[0031] In a further advantageous embodiment, an overlap circle segment is determined based on an overlap of the range of cleaning elements with the inner circle.

[0032] The following applies: (a R - a S ) - (r A - r I ) > h min : obstacle can be cleaned edgelessly by any number of passes; (a R - a S ) - (r A - r I ) ≤ h min : obstacle cannot be cleaned edgelessly by any number of passes; where h min specifies a minimum height of the overlapping circle segment between the inner circle and the area swept by the cleaning element. The specification of the minimum height of the overlapping circle segment h min prevents too many driving maneuvers from being carried out around the obstacle and is determined from the generally maximum permitted number of driving maneuvers and the current inner circle radius.

[0033] In a further advantageous embodiment, a center angle is determined based on the overlap segment, with the number of driving maneuvers preferably being determined using the center angle. In particular, the following formula applies to h min: h min = r I * 1 − cos α min / 2 with minimum central angle α min of the circle segment: α min = 2 * π / N max , where N max is the maximum number of permitted passes. Once it is ensured that there is a sufficient overlap segment between the reach of the cleaning element and the inner circle, it is possible to calculate how many straight-line maneuvers are necessary at the obstacle to ensure edge-to-edge cleaning. To do this, the first step is to calculate the actual height h of the overlapping circle segment of the inner circle and the reach line, followed by the resulting central angle α: h = a R − a S − r A − r I ; α = 2 ∗ arcos 1 − h / r I .

[0034] The number N of driving maneuvers can be determined using the central angle α: N = 360 ° / α .

[0035] N is rounded up to the nearest integer (i.e., the smallest integer greater than or equal to the first integer). A difference angle φ diff between adjacent maneuvers is: φ diff = 360 ° / N .

[0036] This means, among other things, that for a center angle α greater than or equal to 180°, two maneuvers are performed, in particular in parallel, opposing paths with φ diff = 180°; for a center angle between 120° and 180°, three maneuvers are performed (with φ diff = 120°); and / or for a center angle between 90° and 120°, four maneuvers are performed (with φ diff = 90°). The selected starting angle is arbitrary, since the obstacle can be cleaned equally from all directions. However, the starting angle is preferably taken into account when planning the cleaning of the area surrounding the obstacle.

[0037] If there is insufficient overlap between the cleaning element and the inner circle, meaning (a R - a S ) - (r A - r I ) ≤ h min , it is not possible to clean the obstacle completely with the existing cleaning element and with straight-line maneuvers. In this case, special movement maneuvers of the device are necessary, for example, to enter concave shapes of the obstacle's contour or to position the cleaning element there precisely.

[0038] In a further advantageous embodiment, it is determined whether the contour of the obstacle has a substantially elongated shape. For this purpose, main axes are determined in particular from the measured values ​​for the obstacle. The first main axis runs along the longest extent. The second main axis is perpendicular to this. If the extent of the obstacle contour in the direction of the second main axis is approximately equal to the diameter of the inner circle, then the obstacle is a long, narrow obstacle. For such obstacles, it is advantageous to drive past both sides along the first main axis in order to clean the edges along the long side. If the inner radius r I is greater than the cleaning range of the device (a R - a S ), additional driving maneuvers perpendicular to the first main axis at the ends of the contour are advantageous.

[0039] Furthermore, the invention relates to a mobile, self-propelled device which is operated as described above and comprises a computing unit which is designed to calculate the number of straight-line driving maneuvers based on a size and / or shape of the obstacle.

[0040] Any features, configurations, embodiments and advantages relating to the method also apply in connection with the device according to the invention, and vice versa.

[0041] The invention is explained in more detail with reference to the following embodiments, which are merely examples. They show: Figure 1: a schematic top view of an embodiment of a mobile, self-propelled device according to the prior art for cleaning chair legs, Figure 2A: a schematic top view of an embodiment of a mobile, self-propelled device according to the invention for cleaning chair legs, Figure 2B: a schematic bottom view of an embodiment of a mobile, self-propelled device according to the invention, Figures 3A-3C: each show schematic top views of obstacles for defining the outer circle and the inner circle, Figures 4A-5B each show schematic top views for defining the outer circle, the inner circle, the range, the minimum distance, the center angle and the height of the overlapping circle segment, and Figure 6 shows a flowchart relating to an embodiment of an operating method according to the invention.

[0042] In Figure 1A mobile, self-propelled device, in particular a vacuum robot 1, is shown, comprising a suction nozzle 2, drive wheels 3a, 3b, and a cleaning element 4, in particular a side brush. The side brush is arranged at a front right corner of a housing of the vacuum robot 1 and enables improved edge and corner cleaning.

[0043] To clean small obstacles 5, such as chair or table legs, the robot vacuum cleaner 1 is conventionally designed to move around the leg to be cleaned with the side brush. However, due to the size of the suction nozzle, the positioning of the side brush, and the shape of the device housing, there is a risk that an area 6 surrounding the obstacle 5, or a circular edge around the obstacle 5, may remain uncleaned.

[0044] In order to enable edge-to-edge cleaning around smaller obstacles, straight-line driving maneuvers 9 from different directions are used according to the invention, as is the case, for example, in Figure 2A The number of straight passes required for this can be derived, among other things, from the size and shape of the obstacle 5. According to the invention, improved edge cleaning is achieved by optimizing the driving strategy of the vacuum robot 1.

[0045] The robot vacuum cleaner has a cleaning element 4, for example a rotating side brush, a fixed bristle strip or a cleaning cloth on one of its front corners, which protrudes beyond its contour, as shown in the Figures 2A, 2Bis shown. The housing is preferably D-shaped. Alternatively, the vacuum robot can have a round shape. With its drive wheels 3a, 3b, a caster wheel 7, and the control device, the vacuum robot is able to travel in straight paths in any direction on the floor to be cleaned. In order to detect and scan obstacles in the floor processing area, and to determine their shape and size, a lidar sensor (not shown) is used, which is arranged on a rear area of ​​the device housing and projects beyond it. Based on the derived shape and size of the detected obstacle 5, as well as based on a range 8 of the cleaning element 4 and a desired minimum distance between the vacuum robot and the obstacle 5 during the pass-by, the necessary number of straight-line driving maneuvers 9, in particular pass-bys, can be determined.In particular, the cleaning around obstacle 5 can be planned in advance.

[0046] For the planning of the straight-line driving maneuvers, the smallest outer circle 10 touching the contour of the obstacle 5 at least at two outer corner points and an inner circle 11 concentrically arranged in the center of the outer circle 10 and adjacent to the innermost edge are determined in a first step. Figures 3A, 3B, 3C Examples of different obstacles 5 with different contours 12 are shown. For the different obstacles 5, the outer or enveloping outer circle 10 and the inner inner circle 11 are determined in particular.

[0047] The rectilinear driving maneuver according to the invention is used in particular only for obstacles 5 classified as small. Whether a detected obstacle 5 is classified as small is determined by checking the outer circle 10. If the radius r A of the outer circle 10 exceeds a predefined threshold value r G , the vacuum robot 1, with its protruding cleaning element 4, achieves edge-to-edge cleaning even when circling the obstacle 5 normally by means of edge tracking along the contour 12. The rectilinear driving maneuver according to the invention is not necessary in this case. Obstacles whose radius r A of the outer circle 10 is below the predefined threshold value r G cannot be cleaned edge-to-edge by means of the edge tracking maneuver. For edge-to-edge cleaning, the rectilinear driving maneuver according to the invention for circling the obstacle 5 is used in this case.

[0048] To ensure that edge-to-edge cleaning and passing the obstacle 5 from any direction with the minimum distance are possible, the difference between the outer circle radius r A and the inner circle radius r I (r A - r I ) is compared with the effective range of the cleaning element (range a R - minimum distance a S ). The more similar the contour 12 of the obstacle 5 is to a circle, the smaller the difference between the circle radii (r A - r I ) and the easier it is to reach all obstacle edges while passing. The range of the cleaning element and the minimum distance from the vacuum robot to the obstacle as well as the circle radii are shown in the Figures 4A and 4B clarified.

[0049] In the Figures 5A, 5BThe test to determine whether an overlap or an overlapping circle segment 13 occurs between the range a R and the inner circle 11 is represented geometrically, which allows a statement to be made as to whether the obstacle 5 can be cleaned completely by passing it from any direction. In particular, the following applies: (a R - a S ) - (r A - r I ) > h min : Obstacle 5 can be cleaned completely by any number of passes; (a R - a S ) - (r A - r I ) ≤ h min : Obstacle 5 cannot be cleaned completely by any number of passes; where h min specifies a minimum height of the overlapping circle segment 13 between the inner circle 11 and the area swept by the cleaning element. The specification of the minimum height of the overlapping circle segment h min prevents too many driving maneuvers from being carried out around obstacle 5 and is determined from the generally maximum permitted number of driving maneuvers and the current inner circle radius r I .

[0050] The overlap of the range a R of the cleaning element and the inner circle 11 results in an overlapping circle segment 13, which is defined by its height h and the central angle α (see Figure 5B ).

[0051] For h min the following applies in particular: h min = r I * 1 − cos α min / 2 with minimum central angle α min at the center 14 of the overlapping circle segment 13: α min = 2 * π / N max , where N max is the maximum number of permitted passes. Once it is ensured that there is a sufficient overlap segment 13 between the range a R of the cleaning element and the inner circle 11, it is possible to calculate how many straight-line maneuvers at the obstacle 5 are necessary to ensure edge-to-edge cleaning. To do this, in a first step, the actual height h of the overlap circle segment 13 of the inner circle 11 and the range line a R is calculated, followed by the resulting central angle α: h = a R − a S − r A − r I ; α = 2 * arcos 1 − h / r I .

[0052] With the central angle α, the number N of driving maneuvers can be determined by N = 360 ° / α rounded up to the nearest integer greater than or equal to N. A difference angle φ diff between adjacent driving maneuvers is: φ diff = 360 ° / N . If there is insufficient overlapping circle segment 13 between the cleaning element and the inner circle 11, i.e., (a R - a S ) - (r A - r I ) ≤ h min , it is not possible to clean the obstacle 5 completely with the existing cleaning element and with straight-line maneuvers. In this case, special movement maneuvers of the device are necessary, for example, to enter concave shapes of the contour of the obstacle 5 or to position the cleaning element there specifically.

[0053] In Figure 6 A flowchart of an operating procedure for edgeless obstacle cleaning is shown. A simplified procedure is shown (on the left in the diagram), in which straight passes are made in any direction. The paths shown on the right require complex calculations that are tailored to the shape and orientation of the obstacle.

[0054] In the first step 20, the obstacle to be avoided is scanned or detected, particularly from multiple directions, using the robot vacuum's lidar sensor. Using the scanned values, the outer perimeter of the obstacle can be determined in step 21.

[0055] If the radius of the outer circle r A falls below a predefined threshold value r G (r A < r G ), the inner circle and its inner circle radius r I are determined (step 22a). If (a R - a S ) - (r A - r I ) > h min , the center angle α of the overlapping circle segment is determined (step 23a). In step 24a, the number N of straight-line driving maneuvers and the difference angle are then determined. Finally, the travel path or the travel trajectories of the vacuum robot for cleaning close to obstacles can be planned (step 25).

[0056] If, after step 21, the radius of the outer circle r A exceeds the predefined threshold r G (r A ≥ r G ), the cleaning element of the vacuum robot can achieve edge-to-edge cleaning during normal edge-following travel along the contour of the obstacle. The path or trajectories of the vacuum robot for cleaning close to the obstacle can be planned without further calculation (step 25).

[0057] If, after step 22a, (a R - a S ) - (r A - r I ) ≤ h min , the main axes of the obstacle are determined (step 23b). If the extent along a second main axis corresponds approximately to r I , cleaning is carried out parallel to the main axes (step 24b), and the travel path or travel trajectories of the vacuum robot are planned accordingly. If, however, the extent along the second main axis is >> r I , special processing is necessary (step 24c) in order to plan the travel path or travel trajectories of the vacuum robot (step 25).

[0058] All steps 20-25 are automatically performed or determined by the device after the obstacle has been detected. User intervention is advantageously not necessary. The device independently determines which environmental cleaning mode to perform based on the determined or detected values.

Claims

1. Method for operating a mobile, self-propelled device (1), in particular floor cleaning device, such as a suction and / or sweeping and / or mopping robot, with which the following method steps are carried out: - detecting at least one obstacle (5) in a floor processing area, - cleaning an area surrounding an obstacle (5) by way of at least two straight-line manoeuvres (9) at the obstacle (5) from different directions, - wherein the number (N) and direction of the straight-line manoeuvres (9) is based on a size and / or shape of the obstacle (5), and - wherein a plan for the manoeuvre is determined by means of an outer circle (10) which envelopes a contour of the obstacle (5) and by means of an inner circle (11) which borders the inner contour of the obstacle (5), characterised in that the straight-line manoeuvres (9) are carried out if a radius (rA) of the outer circle (10) does not exceed a predefined threshold value (rG).

2. Method according to claim 1, wherein the number (N) of the straight-line manoeuvres (9) is further based on a range (8) of cleaning elements (4) of the device (1) and / or on a predetermined minimum distance between the device (1) and obstacle (5).

3. Method according to one of the preceding claims, wherein an overlap circle segment (13) is determined based on an overlap of the range (8) of cleaning elements (4) with the inner circle (11).

4. Method according to claim 3, wherein a centre angle (α) is determined based on an overlap circle segment (13).

5. Method according to claim 4, wherein the number (N) of the manoeuvres is determined by the centre angle (α).

6. Method according to claim 4 or 5, wherein two manoeuvres are carried out when a centre angle (α) is greater than or equal to 180°, three manoeuvres are carried out when a centre angle is between 120° and 180°, inclusive, and / or four manoeuvres are carried out when a centre angle is between 90° and 120°, inclusive.

7. Mobile, self-propelled device (1), which is operated according to one of the preceding claims, and comprises a computing unit which is designed to calculate the number (N) of the straight-line manoeuvres (9) based on a size and / or shape of the obstacle (5).