Robotic lawnmower with improved cutting characteristics

Abstract

The present disclosure relates to a robotic lawnmower (100) having a first end portion (101) and a second end portion (102) and including a body (140), at least two drive wheels (130a, 130b), at least one rotatable wheel (131a, 131b), a rotatable grass-cutting disk (160) having an axle (152), and at least two electric motor units (150, 165). The at least two drive wheels (130a, 130b) have a drive wheel axle (145) with a center (146) and are drivingly coupled to the first electric motor unit (150), and the at least one rotatable wheel (131a, 131b) has a corresponding axle (153, 154). A pivot mounting axis (151) passing through at least one pivot axis (153, 154) and parallel to the drive axle (145) is positioned between the second end portion (102) and the drive axle (145). A cutting disc (160) is drivingly connected to a second electric motor unit (165), the cutting disc (160) being at least partially positioned between the pivot mounting axis (151) and the second end portion (102).

Description

Technical Field

[0001] The present disclosure relates to a robotic lawn mower adapted to operate within a certain operating range. The robotic lawn mower includes a main body, at least two drive wheels, at least one swiveling wheel, a control unit adapted to control the operation of the robotic lawn mower, a rotatable grass cutting disk having a rotating shaft, and at least two electric motor devices.

Background Art

[0002] Robotic lawn mowers, such as robotic lawn mowers, are becoming increasingly popular. Robotic lawn mowers are typically battery-powered using rechargeable batteries and are adapted to automatically cut the grass of the user's lawn. The robotic lawn mower can be automatically charged without user intervention and does not require manual management once set.

[0003] In a typical deployment within a work area such as a garden, park, sports field, golf course, etc., the work area is surrounded by a boundary wire for the purpose of keeping the robotic lawn mower within this work area. An electrical control signal can be transmitted through the boundary wire, thereby generating an (electro)magnetic field emitted from the boundary wire. The robotic work tool is typically arranged with one or more sensors adapted to detect the control signal.

[0004] Alternatively, or in addition, the robotic lawn mower can be equipped with a navigation system adapted for a system such as GPS (Global Positioning System) or any other global navigation satellite system (GNSS) using, for example, real-time kinematic (RTK).

[0005] One problem associated with robotic lawn mowers is their limited ability to cut grass near objects and borders. That is, typically, the cutting unit is disposed below the lawn mower body of the robotic lawn mower, and each part of the lawn mower body and / or the wheels attached thereto may prevent the cutting unit from reaching the grass near the object and the border. In such a case, uncut grass will exist near objects such as trees, stones, furniture, and the walls of buildings, thus compromising the cutting result.

[0006] Another problem associated with robotic lawn mowers is that, due to safety reasons, robotic lawn mowers have a limited clearance height from the ground, and thus have a limited ability to cut relatively long grass.

[0007] Therefore, there is a desire to provide means and methods for cutting grass near objects and borders and for cutting relatively long grass. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The object of the present disclosure is to provide means and methods for cutting grass near objects and borders and for cutting relatively long grass. MEANS FOR SOLVING THE PROBLEMS

[0009] This object is achieved by using a robotic lawn mower having a first end portion and a second end portion. The robotic lawn mower includes a body, at least two drive wheels, at least one swiveling wheel, a control unit adapted to control the operation of the robotic lawn mower, a rotatable grass cutting disk having a rotation axis, and at least two electric motor devices. The at least two drive wheels are provided with a drive wheel axis having a center and are drivably connected to the first electric motor device, and the at least one swiveling wheel has a corresponding swivel axis. A swivel mounting axis passing through the at least one swivel axis and parallel to the drive wheel axis is positioned between the second end portion and the drive wheel axis. The cutting disk is drivably connected to the second electric motor device, where the cutting disk is positioned between the swivel mounting axis and the second end portion.

[0010] In this way, the cutting disk is positioned in such a way that it can move laterally in an arc shape when the drive wheels are driven in different rotational directions by the first electric motor device. Thus, the cutting disk can reach relatively close to the edge.

[0011] According to some embodiments, when the rotation axis passes through the cutting disk, the rotation axis is positioned between the swivel mounting axis and the second end portion.

[0012] In this way, the cutting disk is positioned in such a way that it can move laterally in an arc shape when the drive wheels are driven in different rotational directions by the first electric motor device.

[0013] According to some aspects, the control unit is adapted to control the robotic lawn mower to move towards the boundary such that the first end portion approaches the boundary, and to determine whether the distance to the boundary meets the condition. If so, the control unit stops the robotic lawn mower and controls the drive wheels to rotate the cutting disks in different directions so that the second end portion of the robotic lawn mower performs an arcuate motion along the cutting arc, enabling the cutting disks to cut the grass inside the cutting arc.

[0014] In this way, it becomes possible to cut the grass relatively close to the edge.

[0015] According to some aspects, the center of the cutting arc is positioned along the drive wheel axis. According to some aspects, the center of the cutting arc is positioned at the center of the drive wheel axis.

[0016] This means that an arcuate motion can be easily performed by rotating the drive wheels in different directions.

[0017] According to some aspects, the boundary is in the form of a boundary wire that defines the operating area for the robotic lawn mower, where the control unit is adapted to stop the robotic lawn mower (when the robotic lawn mower is positioned on the boundary wire). The condition relates to the determined distance between the boundary wire and the robotic lawn mower being below a first threshold.

[0018] According to some aspects, the boundary is in the form of an object, where the cutting arc has a closest arc portion closest to the object, and the condition relates to the determined distance between the object and the robotic lawn mower being below a second threshold.

[0019] Obviously, the boundary can be in many forms, but it is still possible to cut the grass relatively close to the boundary.

[0020] According to some aspects, the cutting arc has an extension of an angle exceeding 180°, and the control unit is adapted to control the robotic lawn mower to continue moving when the second end center following the extension of the cutting arc reaches the end of the cutting arc.

[0021] This means that the robotic lawn mower will continue to move at a constant angle relative to the initial approach angle away from the boundary. Thus, now the robotic lawn mower can repeat the above procedure to perform an arcuate movement so that the continuous grass edge near the boundary can be cut. This can be combined with cutting the remaining grass on the lawn.

[0022] According to some aspects, the robotic lawn mower further includes a first arcuate protective wall that at least partially passes along the second end portion, and at least one additional arcuate protective wall. The protective walls extend from the body towards the ground (G) during normal operation, and the protective walls are radially spaced apart.

[0023] Viewed from the position of the cutting disk, the protective walls provide injury protection for humans and animals approaching the second end portion during normal operation.

[0024] According to some aspects, the protective walls at least mainly follow the arcs of their respective protective walls, and the arcs of all the protective walls have a common center. According to some aspects, the common center is the center of the drive wheel axle.

[0025] In this way, when the arcuate movement is performed, the grass will not bend when moving between the protective walls.

[0026] According to some aspects, the arcuate extension of at least one protective wall that at least mainly follows the arcs of their respective walls includes a tapered end portion.

[0027] As a result, when an arc-shaped movement is performed, the grass can be easily divided between the protective walls.

[0028] According to some aspects, the second electric motor device is positioned closer to the drive wheel axis than to the rotation axis. In this way, the weight of the second electric motor device is positioned closer to the drive wheels, thereby providing improved traction.

[0029] According to some aspects, the robotic lawn mower is adapted for forward and reverse directions, with the first end portion facing the forward direction and the second end portion facing the reverse direction.

[0030] In this way, when the protective wall is positioned at the second end portion, relatively tall grass can thus enter between the robotic lawn mower and the ground without bending or with only slight bending before reaching the cutting disk. This is advantageous as it provides more efficient cutting of the grass and is made possible by positioning the cutting disk relatively close to the second end portion.

[0031] According to some aspects, the robotic lawn mower includes a cutting disk device, where the cutting disk device includes a cover component having successive cutting apertures. The cover component is positioned between the cutting disk and the ground during normal operation and at least mainly covers the side of the cutting disk facing the ground during normal operation.

[0032] This provides improved protection from the cutting blade portion.

[0033] According to some aspects, the cutting disk device is displaceable in a manner that allows adjustment of the distance between the cutting disk and the ground.

[0034] This provides improved control of the grass cutting height.

[0035] According to some aspects, the front portion includes a housing wall that at least partially encloses a cutting disk.

[0036] This provides improved protection from the cutting blade.

[0037] According to some aspects, the cutting disk apparatus similarly includes one or more protective walls that at least partially pass along a second end portion, where the protective walls extend from the body towards the ground during normal operation and are radially spaced apart.

[0038] This provides improved protection from the cutting blade.

[0039] According to some aspects, the one or more protective walls are divided into two parts separated by the cutting disk and its cover components.

[0040] In this way, the protective wall is integrated with the cutting disk apparatus.

[0041] According to some aspects, the control unit is adapted to control a second electric motor device to rotate the cutting disk in a first rotational direction and a second rotational direction opposite to the first rotational direction. The control unit is further adapted to control the second electric motor device to rotate the cutting disk in a rotational direction that coincides with the current cutting direction up to a maximum extent where the cutting disk is closest to the second end portion.

[0042] In this way, improved cutting results and less clogging are provided.

[0043] The present disclosure is similarly related to a method associated with the above advantages.

[0044] Generally, all terms used in the claims should be interpreted according to their ordinary meanings in the technical field, unless explicitly defined otherwise in this specification. All references to "an element, apparatus, component, means, step, etc." should be construed liberally as meaning at least one instance of that element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly stated. Further features and advantages of the present disclosure will become apparent upon consideration of the appended claims and the following description. Those skilled in the art will recognize that, without departing from the scope of the present disclosure, different features of the present disclosure can be combined to create embodiments other than those described below.

[0045] Here, the present disclosure will be described in further detail with reference to the following accompanying drawings.

Brief Description of the Drawings

[0046]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0047] Here, aspects of the present disclosure will be described in more detail below with reference to the accompanying drawings. However, the different devices, systems, computer programs, and methods disclosed herein can be implemented in many different forms and should not be construed as limited to the aspects described herein. Like numbers in the drawings mean like elements throughout.

[0048] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the present disclosure. The articles “a,” “an,” and “the” as used herein are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0049] FIG. 1 shows a top view of the robotic lawn mower 100, FIG. 2 shows a bottom view of the robotic lawn mower 100, and FIG. 3 shows a side perspective bottom view of the robotic lawn mower. The robotic lawn mower 100 has a first end portion 101 and a second end portion 102 and is adapted for a forward direction F and a reverse direction R. According to some aspects, the first end portion 101 faces the forward direction F and the second end portion 102 faces the reverse direction R. The robotic lawn mower 100 includes a body 140, at least two drive wheels 130a, 130b, at least one swiveling wheel 131a, 131b, a control unit 110 adapted to control the operation of the robotic lawn mower 100, a rotatable grass cutting disk 160 having a rotating shaft 152, and at least two electric motor devices 150, 165 (only schematically labeled in FIG. 2). The at least one swiveling wheel has corresponding swivel shafts 153, 154.

[0050] According to some aspects, as illustrated in this embodiment, the robotic lawn mower 100 includes four wheels, two larger drive wheels 130a, 130b and two smaller swiveling wheels 131a, 131b in the form of caster wheels and arranged to swivel around the corresponding swivel shafts 153, 154 when the robotic lawn mower 100 is changing direction. For this purpose, the swiveling wheels 131a, 131b are connected to the body 140 using corresponding swivel wheel holders 158a, 158b, where, according to some aspects, the swivel wheel holders 158a, 158b swivel with respect to the body and are fixed with respect to the swiveling wheels 131a, 131b. The reverse is of course also conceivable.

[0051] The robotic lawn mower 100 can be of a multi-chassis type or a mono-chassis type. The multi-chassis type includes two or more main body parts that are movable relative to each other. The mono-chassis type includes only one main body part. In this exemplary embodiment, the robotic lawn mower 100 is of the mono-chassis type having a main body part 140. The main body part 140 substantially houses all the components of the robotic lawn mower 100.

[0052] The robotic lawn mower 100 also includes at least one rechargeable power source such as a battery 155 (only schematically labeled in FIG. 1) for providing power to the electric motor devices 150, 165. The battery 155 is arranged to be charged using the received charging current from a charging station that receives power through a charging skid 156 or other suitable charging connector. Electromagnetic induction charging without galvanic contact using only electrical contacts is also similarly conceivable. The battery generally consists of a rechargeable power source 155 that can include one or more batteries that can be arranged separately or integrated to form a combined-type battery.

[0053] According to some aspects, the robotic lawn mower 100 may further include at least one navigation sensor device 175 and / or at least one wire sensor 173 (only schematically labeled in FIG. 1). In one embodiment, the navigation sensor device 175 includes one or more sensors for dead reckoning navigation. Examples of sensors for dead reckoning navigation include, among others, an odometer, an accelerometer, a gyroscope, and a compass. The navigation sensor device 175 may include a GPS (Global Positioning System) device, or, according to some aspects, a satellite navigation sensor such as another global navigation satellite system (GNSS) device using, for example, real-time kinematic (RTK).

[0054] The wire sensor 173 is adapted to detect a boundary wire control signal, and / or at least one of the environment detection devices 170, 171 is adapted to detect an object. In this embodiment, radar transceivers 170, 171 are provided and are adapted to transmit signals and receive reflected signals reflected by an object. Other environment detection devices such as a camera device, an ultrasonic device, and a lidar device can of course be conceived as alternatives or in any suitable combination.

[0055] When the robotic lawn mower 100 is moving, the control unit 110 is adapted to control the environment detection devices 170, 171 and control the speed and direction of the robotic lawn mower 100 according to the information collected using the environment detection devices 170, 171 and / or the wire sensor 173.

[0056] The drive wheels 130a, 130b include a drive wheel shaft 145 having a center 146 and are drivably connected to a first electric motor device 150. A swivel mounting shaft 151 that passes through at least one of the swivel shafts 153, 154 and is parallel to the drive wheel shaft 145 is positioned between the second end portion 102 and the drive wheel shaft 145. That is, the maximum first axial distance d 1 between the swivel mounting shaft 151 and the second end portion 102 2 is less than the maximum second axial distance d between the drive wheel shaft 145 and the second end portion 102.

[0057] According to some aspects, at least two drive wheels 130a, 130b form a pair of drive wheels having a drive wheel shaft 145 with a center 146, and this center is positioned between the pair of drive wheels 130a, 130b.

[0058] The first electric motor device 150 is adapted to drive the drive wheels 130a, 130b in the same or different rotational directions and at different rotational speeds. According to some aspects, the first electric motor device 150 includes two separate electric motors, and according to some further aspects, each such electric motor is assembled, for example, within a corresponding drive wheel hub to the corresponding drive wheels 130a, 130b.

[0059] The cutting disk 160 is drivably coupled to a second electric motor device 165 shaped as a cutter motor in this embodiment. According to some aspects, the cutting disk 160 includes a plurality of cutting edges 157, and in this embodiment, three cutting edges 157 are shown (only one is labeled in FIG. 2).

[0060] According to the present disclosure, the cutting disk 160 is positioned at least partially between the pivot mounting shaft 151 and the second end portion 102. This means that at least a portion of the cutting disk 160 is positioned closer to the second end portion 102 than any portion of the pivot mounting shaft 151.

[0061] In this way, the cutting disk 160 is positioned such that it can move in an arcuate shape laterally even when the drive wheels 130a, 130b are driven in different rotational directions by the first electric motor device 150.

[0062] According to some aspects, the rotation axis 152 is positioned between the pivot mounting shaft 151 and the second end portion 102 when the rotation axis 152 penetrates the cutting disk 160. In this way, the cutting disk 160 can easily follow the movement of the second end portion 102, particularly when the drive wheels 130a, 130b are driven in different rotational directions by the first electric motor device 150.

[0063] An embodiment having the advantages of the arrangement of the rotation axis 152 of the cutting disk 160 will be described below.

[0064] According to some aspects, referring to FIG. 6, the control unit 110 controls the robotic lawn mower 100a to move the robotic lawn mower 100 in the forward direction F such that the first end portion 101 approaches the boundaries 182, 220, and is adapted to determine whether the distance to the boundaries 182, 220 meets the condition. If the condition is met, the control unit 110 stops the robotic lawn mower 100b and controls the drive wheels 130a, 130b to rotate in different directions from each other, so that the second end portions 102 of the robotic lawn mowers 100c, 100d perform an arcuate motion along the cutting arc 210, and the cutting disk 160 is adapted to cut the grass inside the cutting arc 210. Thus, FIG. 6 illustrates the robotic lawn mowers 100a, 100b, 100c, 100d, 100e at different positions taken at different times.

[0065] In this way, it is possible to cut the grass relatively close to the edge.

[0066] According to some aspects, the boundary is in the form of a boundary wire 220 that defines the operating area for the robotic lawn mower 100, where the control unit 110 is adapted to stop the robotic lawn mower 100 when the robotic lawn mower 100 is positioned on the boundary wire 220. At this time, the robotic lawn mower 100b is positioned at a certain distance from the lawn edge 139, and the boundary wire 220 is positioned at a certain distance from the lawn edge 139. This distance is adapted such that the grass is cut up to the lawn edge 139 when the robotic lawn mowers 100c, 100d perform an arcuate motion, and the cutting arc 210 has the closest arc portion 211 closest to the lawn edge 139. In this embodiment, the condition relates to the determined distance between the boundary wire 220 and the robotic lawn mower 100 being less than a first threshold value. This means that some predetermined reference point of the robotic lawn mower 100 enters a distance below a second threshold value, for example, the wire sensor 173.

[0067] According to some embodiments, the boundary is shaped like the object 182, and at this time, the robotic lawn mower 100b is positioned at a certain distance from the object 182, and this distance is adapted such that the grass is cut up to the object 182 when the robotic lawn mowers 100c, 100d perform an arcuate motion. The cutting arc 210 has a closest arc portion 211 that is closest to the object 182. In this embodiment, the condition relates to the determined distance between the object 182 and the robotic lawn mower 100 being below a second threshold value. This means that some predetermined reference point of the robotic lawn mower 100 enters a distance below the second threshold value, for example, at least one of the environmental detection devices 170, 171.

[0068] According to some embodiments, the condition relates to the robotic lawn mower 100 coming into contact with the object 182, which can be detected, for example, by a collision sensor and / or a radar transceiver 170 and / or a camera device.

[0069] FIG. 6 illustrates both the case where the boundary is in the form of the boundary wire 220 and the case where the boundary is in the form of the object 182. Thus, the boundary can take many forms and still enable relatively close cutting of the grass using the robotic lawn mower 100 that performs the arcuate motion described above.

[0070] According to some embodiments, the object can take the form of a lawn edge 139. According to some embodiments, the object can be detected by any one of the environmental detection devices 170, 171 and / or the navigation sensor device 175 that may include a satellite navigation sensor, either alone or in any suitable combination thereof. This means that, for example, the lawn edge 139 can be detected using the wire sensor 173, the environmental detection devices 170, 171, and / or the navigation sensor device 175, either alone or in both combinations.

[0071] According to some embodiments, the center 159 of the cutting arc 210 is positioned along the drive wheel axis 145. According to some embodiments, the center 159 of the cutting arc 210 is positioned at the center 146 of the drive wheel axis 145. This is the case when the drive wheels 130a, 130b are driven at the same rotational speed in different rotational directions by the first electric motor device 150. Of course, small deviations may occur due to motor inaccuracies, uneven ground, non-uniform grounding and non-uniform ground friction, so this should not be interpreted literally. The fact that the speeds are the same and the center 159 of the cutting arc 210 is positioned at the center 146 of the drive wheel axis 145 should be interpreted according to what is intended and actually achievable, and mathematical accuracy is not required.

[0072] According to some embodiments, the cutting arc 210 has an extension φ at an angle exceeding 180°, where the control unit 110 is adapted to control the robotic lawn mower 100e to continue moving even when the second end center 106, which according to some embodiments constitutes the last part, following the extension of the cutting arc 210, reaches the end 212 of the cutting arc 210. This means that the robotic lawn mower 100e moves away from the boundaries 182, 220 and continues to move at a constant angle with respect to the initial entry angle. This in turn enables the robotic lawn mower 100 to repeat the above procedure to perform an arc-shaped movement, thus enabling continuous grass edges close to the boundaries 182, 220 to be cut. This can be combined with the cutting of the remaining grass on the lawn.

[0073] According to some embodiments, the lawn mower 100 can be adapted to set a mode in which only continuous grass edges close to the boundaries 182, 220 are cut and the remaining lawn is not cut in between. This mode can be selected by the user.

[0074] According to some embodiments, with reference to FIGS. 4 and 5 as well, the robotic lawn mower 100 further includes a first arcuate protective wall 141 that at least partially passes along the second end portion 102, and at least one additional arcuate protective walls 142, 143, 144. The protective walls 141, 142, 143, 144 extend from the main body 140 towards the ground G during normal operation, and the protective walls 141, 142, 143, 144 are radially spaced apart.

[0075] In this embodiment, there are four protective walls 141, 142, 143, 144, namely the first protective wall 141, the second protective wall 142, the third protective wall 14 and the fourth protective wall 144. The cutting disc 160 is positioned at least partially between the pivot mounting shaft 151 and the second end portion 102. According to some embodiments, since the rotation axis 152 is positioned between the pivot mounting shaft 151 and the second end portion 102 when the rotation axis 152 passes through the cutting disc 160, the protective walls 141, 142, 143, 144 provide injury protection for humans and animals approaching the second end portion 102 during normal operation.

[0076] There is a first distance h between the first protective wall 141 and the ground G 1 and here the first distance h 1 naturally varies slightly during operation. There is a second distance h between the first end portion 101 and the ground G 2 and here the second distance h 2 naturally varies slightly during operation as well. In this embodiment, the first distance h 1 is less than the second distance h 2 and in the case of the first end portion 101, it faces the forward direction F, which means that relatively tall grass can enter between the robotic lawn mower 100 and the ground G without bending or with only slight bending before reaching the cutting disc 160. The bouncing effect of the bent grass may require additional distance and thus additional time to return from the bend.

[0077] This is advantageous in that it provides for more efficient cutting of grass and is made possible by positioning the cutting disk 160 relatively close to the second end portion 102 where the cutting disk 160 is protected by the protective walls 141, 142, 143, 144.

[0078] According to some aspects, the protective walls 141, 142, 143, 144 are positioned, at least partially, between the cutting disk 160 and the ground G during normal operation. In this way, while the cutting disk 160 can reach the second end portion 102, humans and animals approaching the second end portion 102 during normal operation are still protected from injury.

[0079] According to some aspects, the protective walls 141, 142, 143, 144 follow at least mainly the arcs 141a, 142a, 143a, 144a of their respective protective walls, and all the arcs 141a, 142a, 143a, 144a of the protective walls have a common center 146. According to some aspects, the common center 146 is the center of the drive wheel axle 145. In this way, when an arcuate movement is performed, the grass will not bend when moving between the protective walls 141, 142, 143, 144. According to some aspects, the protective walls 141, 142, 143, 144 are spaced radially from the common center.

[0080] According to some aspects, the arcuate extensions of at least one of the protective walls 141, 142, 143, which at least mainly follow the arcs 141a, 142a, 143a of their respective walls, include tapered end portions 147, 148, 149. This means that there are tapered end portions 147, 148, 149 at the arcuate ends of at least one of the protective walls 141, 142, 143. In this embodiment, this applies to the first three protective walls 141, 142, 143 and enables the grass to be easily divided between the protective walls 141, 142, 143, 144 when an arcuate movement is performed.

[0081] According to some aspects, it should be pointed out that the rotation axis 152 can be tilted at the incident angle of the cutting disk that constitutes the approach angle α towards the ground G. Such tilting improves the cutting result because the cutting disk 160 is closer to the ground G when facing the forward direction F. When the first end portion 101 faces the forward direction F and the second end portion 102 faces the backward direction R, the first distance h 1 between the first protective wall 141 and the ground G can be increased, which is advantageous.

[0082] It should be pointed out that all position references with respect to the rotation axis 152 are intended to be considered when the rotation axis 152 passes through the cutting disk 160.

[0083] According to some aspects, the second electric motor device 165 is positioned closer to the drive wheel axis 145 than the rotation axis 152. In this way, the weight of the cutter motor 165 is positioned closer to the drive wheels 130a, 130b, which imparts an enhancement of the indexing force. In this case, some output transmission means are required to transmit the rotational output from the cutter motor 165 to the cutting disk 160. Such output transmission means can take the form of, for example, a drive belt, a drive chain or a gear transmission.

[0084] Referring to FIG. 9, the present disclosure also relates to a method for controlling a robotic lawn mower 100 having at least two drive wheels 130a, 130b having a drive wheel shaft 145 with a first end portion 101, a second end portion 102, and a center 146, and being drivably connected to a first electric motor device 150, and at least one swiveling wheel 131a, 131b having at least one swiveling wheel having corresponding swivel axes 153, 154. A swivel mounting shaft 151 passing through at least one of the swivel axes 153, 154 and parallel to the drive wheel shaft 145 is positioned between the second end portion 102 and the drive wheel shaft 145. The robotic lawn mower 100 further has a rotatable grass cutting disk 160 positioned at least partially between the swivel mounting shaft 151 and the second end portion 102.

[0085] The method includes a step S100 of controlling the robotic lawn mower 100a to move towards the boundaries 182, 220 such that the first end portion 101 approaches the boundaries 182, 220, and a step S200 of determining whether the distance to the boundaries 182, 220 satisfies a condition. If satisfied, the method includes a step S300 of stopping the robotic lawn mower 100b and a step S400 of controlling the drive wheels 130a, 130b to rotate in different directions such that the second end portions 102 of the robotic lawn mowers 100c, 100d perform an arcuate motion along the cutting arc 210 and the grass cutting disk 160 can cut the grass inside the cutting arc 210.

[0086] According to some aspects, when the rotation axis 152 passes through the grass cutting disk 160, the rotation axis 152 is positioned between the swivel mounting shaft 151 and the second end portion 102.

[0087] According to some aspects, the cutting arc 210 has an extension with an angle exceeding 180°, where the method includes step S500 of controlling the robotic lawn mower 100e to continue moving after the second end portion center 106 following the extension of the cutting arc 210 reaches the end 212 of the cutting arc 210.

[0088] According to some aspects, the boundary is in the form of a boundary wire 220 that defines the operating area for the robotic lawn mower 100, and the stop step S300 of the robotic lawn mower 100 occurs when the robotic lawn mower 100 is positioned on the boundary wire 220, where the condition relates to a determined distance between the boundary wire 220 and the robotic lawn mower 100 being below a first threshold value.

[0089] According to some aspects, the boundary is in the form of an object 182, the cutting arc has a closest arc portion 211 closest to the object 182, where the condition relates to a determined distance between the object 182 and the robotic lawn mower 100 being below a second threshold value.

[0090] According to some aspects, the condition relates to the robotic lawn mower 100 coming into contact with the object 182, which can be detected, for example, by a collision sensor and / or a radar transceiver 170 and / or a camera device.

[0091] According to some aspects, the cutting arc 210 has an extension with an angle exceeding 180°, and the control unit 110 is adapted to control the robotic lawn mower 100e to continue moving even when the second end center 106 following the extension of the cutting arc 210 reaches the end 212 of the cutting arc 210.

[0092] According to some aspects, the method includes using at least one wire sensor 173 to detect a boundary wire control signal and / or using at least one environmental detection device 170, 171 to detect the object 182.

[0093] According to some aspects, the robotic lawn mower 100 is used for the forward direction F and the reverse direction R, the first end portion 101 faces the forward direction F, and the second end portion 102 faces the reverse direction R.

[0094] In FIG. 7, from the perspective of many functional units, the components of the control unit 110 according to the embodiments of the discussion in this specification are schematically illustrated. For example, a processing circuit 115 is provided using any combination of one or more of a suitable central processing unit CPU, microprocessor, microcontroller, digital signal processor DSP, etc. having the ability to execute software instructions stored in a computer program product in the form of a storage medium 120. The processing circuit 115 may further be provided as at least one application specific integrated circuit ASIC or field programmable gate array FPGA. Thus, the processing circuit includes a plurality of digital logic components.

[0095] In particular, the processing circuit 115 is configured to control the radar transceiver 170, process the measurement results received via the radar transceiver 170, and perform a set of operations or steps for controlling the robotic lawn mower 100 including but not limited to the propulsion of the robotic lawn mower 100. For example, the storage medium 120 can store an operation set, and the processing circuit 115 can be configured to retrieve the operation set from the storage medium 120 and cause the control unit 110 to perform the operation set. The operation set can be provided as a set of executable instructions. Thus, the processing circuit 115 is thus arranged to execute at least a part of the method disclosed herein.

[0096] The storage medium 120 may similarly include a persistent storage device which can be any one or a combination of, for example, a magnetic memory, an optical memory, a solid state storage device, and even a remotely assembled memory.

[0097] According to some aspects, the control unit 110 further includes an interface 112 for communicating with at least one external device such as a user terminal. Thus, the interface 112 may include one or more transmitters and receivers, including analog and digital components, and a suitable number of wired communication ports. The interface 112 may be adapted for communication with devices such as remote servers, charging stations, and / or other robotic work tools. Examples of such wireless communication devices include Bluetooth®, WiFi® (IEEE802.11b), Global System for Mobile (GSM), and Long Term Evolution (LTE), to name a few. This means that, according to some aspects, other units such as remote servers are adapted to partially execute the methods disclosed herein.

[0098] FIG. 8 shows a computer program product 400 including computer-executable instructions 410 stored on a medium 420 for executing any of the methods disclosed herein.

[0099] The present disclosure is not limited to the above and may vary freely within the scope of the appended claims. For example, the first end portion 101 may face the rearward direction R, and the second end portion 102 may face the forward direction F.

[0100] The end portions 101, 102 are shown as arcuate portions facing the forward direction F or the rearward direction R, where, according to some aspects, the first arcuate protective wall 141 constitutes the second end portion 102. According to some aspects, the end portions 101, 102 can be defined as the rearmost or foremost points in the robotic lawn mower 100. According to some aspects, the first end portion 101 is on the opposite side of the second end portion 102, and each end portion faces in one direction of travel.

[0101] According to some aspects, the swivel mounting axis 151 passes through the point where the swiveling wheels 131a, 131b are connected to the body 140 using corresponding swivel wheel holders 158a, 158b.

[0102] According to some aspects, the robotic lawn mower 100 includes at least one protective wall that at least partially passes along or adjacent to the second end portion 102 and extends from the body 140 towards the ground G during normal operation. This protective wall can be linear and / or arcuate, or can have any other suitable shape. In this context, adjacent means that the protective wall is close to the second end portion 102 so as to protect from the cutting blade portion 157 of the cutting disk 160 when the cutting disk 160 is brought close to the second end portion 102.

[0103] The cutting disk 160 is at least partially positioned between the swivel mounting axis 151 and the second end portion 102, and the rotation axis 152 is positioned between the swivel mounting axis 151 and the second end portion 102 when it passes through the cutting disk 160. Thus, the at least one protective wall provides injury protection for humans and animals approaching the second end portion 102 during normal operation. This means that in this embodiment, only a single protective wall that does not need to be arcuate and can have any suitable shape is required.

[0104] In particular, when there are two or more protective walls 141, 142, 143, 144, it is desirable to avoid clogging of the protective walls 141, 142, 143, 144 and improve the cutting quality. During the operation of the robotic lawn mower 100 a difference in cutting performance appears depending on whether the cutting disk 160 is rotating in the cutting direction or rotating in the direction opposite to the cutting direction. Thus, according to some aspects, referring to FIG. 2, the control unit 110 rotates the cutting disk 160 in a first rotation direction r 1 and a second rotation direction r opposite to the first rotation direction r 1 2 ​is adapted to control the second electric motor device 165 to rotate in a particular direction. Specifically, the control unit 110 rotates the cutting disk 160 in the rotational direction r 1 , r 2 in accordance with the cutting direction, and is adapted to control the second electric motor device 165 to rotate in the rotational direction r 1 , m 2 that coincides with the current cutting direction m 1 , r 2 until the cutting disk 160 is closest to the second end portion 102. Here, the cutting direction m 1 , m 2 is the direction in which the second end portion 102 moves during cutting, but other portions can also be used as a reference for the cutting direction m 1 , m 2 in the same manner.

[0105] In this embodiment, when the robotic lawn mower 100 is viewed from the bottom side, the first rotational direction r 1 corresponds to the first cutting direction m 1 , and the second rotational direction r 2 is different from the first cutting direction m 1 , for example, corresponding to the second cutting direction m 1 opposite to the first cutting direction m 2 . Here, the first rotational direction r 1 is the clockwise direction, the second rotational direction r 2 is the counterclockwise direction, the first cutting direction m 1 faces left, and the second cutting direction m 2 faces right. When viewed from the top of the robotic lawn mower 100, the first cutting direction m 1 corresponds to the robotic lawn mower 100 turning left, and the second cutting direction m 2 corresponds to the robotic lawn mower 100 turning right. According to some aspects, when the robotic lawn mower 100 performs an arcuate motion along the cutting arc 210 as described above, the arcuate motion is directed in the cutting direction.

[0106] When the robotic lawnmower 100 moves in a first mowing direction m 1 , the cutting disc 160 is controlled to rotate in a first rotational direction r 1 and when the robotic lawnmower 100 moves in a second mowing direction m 2 , the cutting disc 160 is controlled to rotate in a second rotational direction r 2 .

[0107] This means that the cutting blade 157 always cuts against the direction of the grass, since due to the current cutting direction the grass is brought closer to the cutting blade 157 against the movement of the cutting blade 157. This results in the grass meeting the cutting blade 157 as soon as possible and being released from the protective walls 141, 142, 143, 144. As a result, the cutting result is improved and clogging is less likely.

[0108] According to some embodiments, there is a further cutting disk 180 (only indicated diagrammatically) with a rotating axle 181 positioned between the pivot mounting axle 151 and the drive axle 145, with reference to FIG. 2 . This further cutting disc 180 may constitute the main cutting disc 180 which is active during normal cutting, the cutting disc 160 possibly being disengaged. When the robotic lawnmower 100 is controlled to cut grass relatively close to a boundary, for example by performing the previously described arcuate motion along the cutting arc, the main cutting disc 180 is disengaged and the cutting disc 160 is operatively engaged.

[0109] >According to some embodiments, the main cutting disk 180 has a diameter larger than that of the cutting disk 160, and thus a cutting width. By using the cutting disk 160 only when cutting grass relatively close to the boundary and using the main cutting disk 180 in other cases, energy is saved and efficiency is increased. According to some embodiments, the main cutting disk 180 is adjustable with respect to the grass cutting height manually or automatically by a conventionally known method. This means that the main cutting disk 180 is displaceable so as to be able to adjust the distance between the main cutting disk 180 and the ground G.

[0110] According to some embodiments, referring to FIGS. 10 and 11 showing a perspective bottom view of the front portion 535 of the robotic lawn mower, the robotic lawn mower includes a cutting disk device 563. The cutting disk device 563 includes a rotatable grass cutting disk 560 positioned at least partially between the swivel mounting shaft 551 and the second end portion 502. Alternatively, the rotation axis 552 of the cutting disk 560 is positioned between the swivel mounting shaft 551 and the second end portion 502 when the rotation axis 552 penetrates the cutting disk 560. This positioning corresponds to the rotatable grass cutting disk 160 according to the previous embodiments disclosed above.

[0111] In this embodiment, the cutting disk device 563 includes a cover part 561 that sequentially includes cutting apertures 562 (only a few are shown for clarity). The cover part 561 is positioned between the cutting disk 560 and the ground G during normal operation (shown in FIG. 5), and at least mainly covers the side of the cutting disk 560 facing the ground G during normal operation. According to some embodiments, the cover part 560 includes an opening 532 that enables access to the cutting disk 560, which is suitable, for example, when replacing or sharpening the cutting blade part.

[0112] Thus, improved protection from the cutting blade part is provided.

[0113] According to some aspects, the cutting disk device 563 is displaceable to adjust the distance between the cutting disk 560 and the ground G. In FIG. 5, the minimum distance h between the cutting disk 560 and the ground G is indicated. This can be achieved in a number of ways. For example, the cutting disk device 563 can be slidably disposed within an orbit and can be locked in a suitable position using one or more screws (not shown). This is illustrated in FIGS. 10 and 11, where FIG. 10 shows the cutting disk device 563 in a first position and FIG. 11 shows the cutting disk device 563 in a second position. In the first position, the distance h between the cutting disk 560 and the ground G is smaller than in the case of the second position. c This thus facilitates the control of the grass cutting height. c is smaller than in the case of the second position.

[0114] In this way, the control of the grass cutting height is easily improved.

[0115] According to some aspects, the front portion 535 includes a housing wall 564 that at least partially encloses the cutting disk 560. The housing wall 564 can be included, for example, within the cutting disk device 563.

[0116] According to some further aspects, the cutting disk device 563 also includes one or more protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b that at least partially pass along the second end portion 502. The protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b extend from the lawn mower body 540 towards the ground G and are radially spaced apart during normal operation, similar to the protective walls according to the embodiments disclosed above.

[0117] According to some embodiments, one or more protective walls are divided into two parts 542a, 542b, 543a, 543b, 544a, 544b separated by a cutting disk 560 and its cover part 561. The protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b may be separate from the cutting disk device 563. Alternatively, according to some embodiments, at least one or more protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b are included within the cutting disk device 563.

[0118] In the latter case, as illustrated in FIGS. 10 and 11, all of the protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b are included within the cutting disk device 563. That is, when the cutting disk device 563 is displaced to adjust the distance between the cutting disk 560 and the ground G, at least one or more of the protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b included within the cutting disk device 563 are similarly displaced to correspond as shown in FIGS. 10 and 11.

[0119] Furthermore, according to some embodiments, there is a first protective wall 541 that is closest to the second end portion 502 and is not separated. There are three additional protective walls 542a, 542b; 543a, 543b; 544a, 544b that are separated by the cutting disk 560 and its cover part 561 to form six protective sub-walls 542a, 542b, 543a, 543b, 544a, 544b. In this way, the protective walls are integrated with the cutting disk device.

[0120] According to some embodiments, one or more of the protective walls 542a, 542b, 543a, 543b, 544a, 544b at least mainly follow the arc of each protective wall as described for the previous embodiments disclosed above.

[0121] According to some aspects, the cutting disks 160, 560 themselves are displaceable such that the protective wall remains fixed to the main body 140 and the distance between the cutting disks 160, 560 and the ground G can be adjusted. In this case, the main body 140 can provide a sufficient protection range such that the cover part 561 is not very necessary.

[0122] Alternatively, if the protective wall is integrated with the cutting disk device and follows the cutting disk 560 when the protective walls 541; 542a, 542b, 543a, 543b, 544a, 544b are displaced, a greater ground clearance is provided, which is advantageous when cutting uneven lawns. In this case, the main body 140 has to be adapted to the maximum ground clearance, and as a result, the protection range becomes narrower, increasing the need for the cover part 561.

[0123] However, it must be pointed out that the cover part 561 is always an optional part that can be added as needed to enhance the protection from the cutting blade.

[0124] In other words, only the cutting disk 160 may be present or only the main cutting disk 180 may be present. At least one cutting disk is displaceable so that the distance between the cutting disks 160, 560 and the ground G can be adjusted manually or automatically. One or more protective walls may be fixed to the main body or adapted to follow the cutting disk 160 when adjusted. In addition, as aspects of the embodiments of the present invention, there are the following. [Aspect 1] A robotic lawn mower (100) having a first end portion (101) and a second end portion (102), comprising a main body (140), at least two drive wheels (130a, 130b), at least one swiveling wheel (131a, 131b), a control unit (110) adapted to control the operation of the robotic lawn mower (100), a rotatable grass cutting disk (160) having a rotation axis (152), and at least two electric motor devices (150, 165). In the robotic lawn mower (100), at least two drive wheels (130a, 130b) are provided with a drive wheel axis (145) having a center (146) and are drivingly connected to a first electric motor device (150). At least one swiveling wheel (131a, 131b) has a corresponding swivel axis (153, 154). A swivel mounting axis (151) passing through at least one swivel axis (153, 154) and parallel to the drive wheel axis (145) is positioned between the second end portion (102) and the drive wheel axis (145). The cutting disk (160) is drivingly connected to a second electric motor device (165), and the cutting disk (160) is positioned at least partially between the swivel mounting axis (151) and the second end portion (102). [Aspect 2] When the rotation axis (152) passes through the cutting disk (160), the rotation axis (152) is positioned between the swivel mounting axis (151) and the second end portion (102). The robotic lawn mower (100) according to Aspect 1. [Aspect 3] Further including at least one protective wall (141, 142, 143, 144) that passes at least partially along or adjacent to the second end portion 102 and extends from the main body 140 towards the ground G during normal operation. The robotic lawn mower (100) according to any one of Aspects 1 or 2. [Aspect 4] A robotic lawn mower (100) according to any one of aspects 1 to 3, further comprising a first arcuate protective wall (141) passing at least partially along the second end portion (102), and at least one further arcuate protective wall (142, 143, 144), the protective walls (141, 142, 143, 144) extending from the body (140) towards the ground (G) during normal operation, and the protective walls (141, 142, 143, 144) being radially spaced apart. [Aspect 5] The robotic lawn mower (100) according to aspect 3, wherein the protective walls (141, 142, 143, 144) are partially positioned between the cutting disk (160) and the ground (G) during normal operation. [Aspect 6] The robotic lawn mower (100) according to any one of aspects 3 or 4, wherein the protective walls (141, 142, 143, 144) at least mainly follow the arcs (141a, 142a, 143a, 144a) of their respective protective walls, and all the arcs (141a, 142a, 143a, 144a) of the protective walls have a common center (146). [Aspect 7] The robotic lawn mower (100) according to aspect 5, wherein the common center (146) is the center of the drive wheel axis (145). [Aspect 8] The robotic lawn mower (100) according to any one of aspects 3 to 6, wherein the arcuate extension portions of at least one of the protective walls (141, 142, 143) that at least mainly follow the arcs (141a, 142a, 143a, 144a) of their respective walls include tapered end portions (147, 148, 149). [Aspect 9] The robotic lawn mower (100) according to any one of aspects 1 to 8, wherein the second electric motor device (165) is positioned closer to the drive wheel axis (145) than the rotation axis (152). [Aspect 10] The control unit (110) controls the robotic lawn mower (100a) to move towards the boundary (182, 220) such that the first end portion (101) approaches the boundary (182, 220); determines whether the distance to the boundary (182, 220) satisfies a condition; and if so, stops the robotic lawn mower (100b); and The second end portion (102) of the robot lawn mower (100c, 100d) performs an arc-shaped movement along the cutting arc (210), and the drive wheels (130a, 130b) are controlled to rotate in different directions so that the cutting disk (160) can cut the grass inside the cutting arc (210). A robot lawn mower (100) according to any one of aspects 1 to 9, adapted as described above. [Aspect 11] The robot lawn mower (100) according to aspect 9, wherein the center of the cutting arc (210) is positioned along the drive wheel axis (145). [Aspect 12] The robot lawn mower (100) according to aspect 10, wherein the center of the cutting arc (210) is positioned at the center (146) of the drive wheel axis (145). [Aspect 13] The boundary is in the form of a boundary wire (220) that defines an operating area for the robot lawn mower (100), and the control unit (110) is adapted to stop the robot lawn mower (100) when the robot lawn mower (100) is positioned on the boundary wire (220), and the condition relates to a predetermined distance between the boundary wire (220) and the robot lawn mower (100) being less than a first threshold value. A robot lawn mower (100) according to any one of aspects 10 to 12. [Aspect 14] The boundary is in the form of an object (182), the cutting arc has a closest arc portion (211) closest to the object (182), and the condition relates to a predetermined distance between the object (182) and the robot lawn mower (100) being less than a second threshold value. A robot lawn mower (100) according to any one of aspects 10 to 13. [Aspect 15] The robot lawn mower (100) according to any one of aspects 10 to 12, wherein the condition relates to the robot lawn mower (100) contacting the object (182). [Aspect 16] The cutting arc (210) has an extension portion with an angle exceeding 180°, and the control unit (110) is adapted to control the robotic lawn mower (100e) to continue moving even when a second end center (106) following the extension portion of the cutting arc (210) reaches the end (212) of the cutting arc (210), the robotic lawn mower (100) according to any one of aspects 10 to 15. [Aspect 17] The robotic lawn mower (100) includes at least one wire sensor (173) adapted to detect a boundary wire control signal and / or at least one environmental detection device (170, 171) adapted to detect an object (182), and / or at least one navigation sensor device (175), the robotic lawn mower (100) according to any one of aspects 1 to 16. [Aspect 18] The robotic lawn mower (100) is adapted for a forward direction (F) and a reverse direction (R), the first end portion (101) faces the forward direction (F), and the second end portion (102) faces the reverse direction (R), the robotic lawn mower (100) according to any one of aspects 1 to 17. [Aspect 19] Including a cutting disk device (563), the cutting disk device (563) includes a cover part (561) sequentially including a cutting aperture (562), and the cover part is positioned between the cutting disk (560) and the ground (G) during normal operation and at least mainly covers the side of the cutting disk (560) facing the ground (G) during normal operation, the robotic lawn mower (100) according to any one of aspects 1 to 18. [Aspect 20] The cutting disk device (563) of the robotic lawn mower (100) according to aspect 19 is displaceable so as to be able to adjust the distance between the cutting disk (560) and the ground (G). [Aspect 21] The front part (535) includes a housing wall (564) at least partially including the cutting disk (560), the robotic lawn mower (100) according to any one of aspects 19 or 20. [Aspect 22] The cutting disk device (563) also includes one or more protective walls (541; 542a, 542b, 543a, 543b, 544a, 544b) that at least partially pass along the second end portion (502), and the protective walls (541; 542a, 542b, 543a, 543b, 544a, 544b) extend from the main body (140) towards the ground (G) and are radially spaced apart during normal operation. A robotic lawn mower (100) according to any one of aspects 19 to 21. [Aspect 23] The robotic lawn mower (100) according to aspect 22, wherein one or more of the protective walls are divided into two parts (542a, 542b, 543a, 543b, 544a, 544b) separated by the cutting disk (560) and its cover part (561). [Aspect 24] The control unit (110) is adapted to control the second electric motor device (165) to rotate the cutting disk (160) in a first rotational direction (r 1 ) and a second rotational direction (r 1 ) opposite to the first rotational direction (r 2 ), and the control unit (110) rotates the cutting disk (160) in a rotational direction (r 1 、m 2 ) that coincides with the current mowing direction (m 1 、r 2 ) until the cutting disk (160) is closest to the second end portion (102). A robotic lawn mower (100) according to any one of aspects 1 to 23. [Aspect 25] A robotic lawn mower (100) having a drive wheel shaft (145) with a first end portion (101), a second end portion (102), and a center (146), at least two drive wheels (130a, 130b) drivenly connected to a first electric motor device (150), and at least one swiveling wheel (131a, 131b) having corresponding swivel axes (153, 154), wherein a swivel mounting shaft (151) passing through at least one swivel axis (153, 154) and parallel to the drive wheel shaft (145) is positioned between the second end portion (102) and the drive wheel shaft (145), and the robotic lawn mower (100) further has a rotatable grass cutting disk (160) positioned at least partially between the swivel mounting shaft (151) and the second end portion (102). In a method for controlling the robotic lawn mower (100): Controlling the robotic lawn mower (100a) to move towards the boundary (182, 220) so that the first end portion (101) approaches the boundary (182, 220) (S100); Determining whether the distance to the boundary (182, 220) meets the condition (S200); if so, Stopping the robotic lawn mower (100b) (S300); Controlling the drive wheels (130a, 130b) to rotate in different directions so that the second end portion (102) of the robotic lawn mower (100c, 100d) performs an arcuate motion along the cutting arc (210) and the cutting disk (160) can cut the grass inside the cutting arc (210) (S400); A method including the above steps. [Aspect 26] The method according to aspect 25, wherein when the rotation axis (152) passes through the cutting disk 160, the rotation axis (152) is positioned between the swivel mounting shaft (151) and the second end portion (102). [Aspect 27] The method according to any one of aspects 25 or 26, including controlling the robotic lawn mower (100e) to continue moving after the second end portion center (106) following the extension of the cutting arc (210) reaches the end (212) of the cutting arc (210), where the cutting arc (210) has an extension portion with an angle exceeding 180° (S500). [Aspect 28] The method according to any one of aspects 25 to 27, wherein the center of the cutting arc (210) is positioned along the drive wheel axis (145). [Aspect 29] The method according to any one of aspects 25 to 28, wherein the center of the cutting arc (210) is positioned at the center (146) of the drive wheel axis (145). [Aspect 30] The boundary is in the shape of a boundary wire (220) that defines an operating area for the robotic lawn mower (100), and when the robotic lawn mower (100) is positioned on the boundary wire (220), the stop (S300) of the robotic lawn mower (100) is executed, and the condition relates to a determined distance between the boundary wire (220) and the robotic lawn mower (100) being less than a first threshold value. The method according to any one of aspects 25 to 29. [Aspect 31] The boundary is in the shape of an object (182), the cutting arc has a closest arc portion (211) closest to the object (182), and the condition relates to a determined distance between the object (182) and the robotic lawn mower (100) being less than a second threshold value. The method according to any one of aspects 25 to 30. [Aspect 32] Using at least one wire sensor (173) for detecting a boundary wire control signal and / or using at least one environment detection device (170, 171) and / or at least one navigation sensor device (175) for detecting an object (182). The method according to any one of aspects 25 to 31. [Aspect 33] The robotic lawn mower (100) is used for a forward direction (F) and a reverse direction (R), the first end portion (101) faces the forward direction (F), and the second end portion (102) faces the reverse direction (R). The method according to any one of aspects 25 to 32. [Aspect 34] Controlling the second electric motor device (165) to rotate the cutting disk (160) in a first rotational direction (r 1 ) and a second rotational direction (r 1) opposite to the first rotational direction (r 2 ); The rotational direction (r 1 、m 2 ) that the cutting disk (160) is closest to the second end portion (102) and coincides with the current mowing direction (m 1 、r 2 ) controlling the second electric motor device (165) to rotate the cutting disk (160); A method according to any one of aspects 25 to 33, comprising:

Claims

1. A robotic lawnmower (100) having a first end portion (101) and a second end portion (102), the robotic lawnmower (100) comprising a body (140), at least two drive wheels (130a, 130b), at least one swivelable wheel (131a, 131b), a control unit (110) adapted to control an operation of said robotic lawnmower (100), a rotatable grass-cutting disk (160) having a rotation axis (152), and at least two electric motor units (150, 165), in which the at least two drive wheels (130a, 130b) are drivably coupled to a first electric motor unit (150) comprising a drive wheel axle (145) having a center (146) and which is one of said at least two electric motor units (150, 165), and the at least one swivelable wheel (131a, 131b) is rotatably coupled to a first electric motor unit (150) having ... corresponding rotation axis (152). a pivot mounting axis (151) passing through at least one pivot axis (153, 154) and parallel to the drive wheel axis (145), the grass-cutting disc (160) is drivably connected to a second electric motor unit (165), the second electric motor unit (165) being another one of the at least two electric motor units (150, 165), the grass-cutting disc (160) being at least partially positioned between the pivot mounting axis (151) and the second end portion (102), and further comprising at least one protective wall (141, 142, 143, 144) extending at least partially along or adjacent to the second end portion (102) and extending from the body (140) towards the ground (G) during normal operation.

2. 2. The robotic lawnmower (100) of claim 1, wherein the rotation axis (152) is positioned between the pivot mounting axis (151) and the second end portion (102) when the rotation axis (152) passes through the grass cutting disc (160).

3. 2. The robotic lawnmower (100) of claim 1, further comprising a first arcuate protective wall (141) extending at least partially along the second end portion (102) and at least one further arcuate protective wall (142, 143, 144), the protective walls (141, 142, 143, 144) extending from the body (140) toward the ground (G) during normal operation, the protective walls (141, 142, 143, 144) being radially spaced apart.

4. 2. The robotic lawnmower (100) of claim 1, wherein the protective wall (141, 142, 143, 144) is positioned partially between the grass-cutting disc (160) and the ground (G) during normal operation.

5. 2. The robotic lawnmower (100) of claim 1, wherein the guard walls (141, 142, 143, 144) at least primarily follow the arcs of each of the guard walls (141a, 142a, 143a, 144a), and all of the guard wall arcs (141a, 142a, 143a, 144a) have a common center (146).

6. The robotic lawnmower (100) of claim 5, wherein the common center (146) is a center of the drive axle (145).

7. 2. The robotic lawnmower (100) of claim 1, wherein an arcuate extension of at least one of the guard walls (141, 142, 143) that at least primarily follows the arc of a respective wall (141a, 142a, 143a, 144a) includes a tapered end portion (147, 148, 149).

8. 2. The robotic lawnmower (100) of claim 1, wherein the second electric motor unit (165) is positioned closer to the drive axle (145) than to the rotational shaft (152).

9. The control unit (110) controlling the robotic mower (100a) to move toward a boundary (182, 220) such that the first end portion (101) approaches the boundary (182, 220); determining whether the distance to the boundary (182, 220) satisfies a condition; and if so, Stopping the robotic lawnmower (100b); and controlling the drive wheels (130a, 130b) to rotate in different directions so that the second end portion (102) of the robotic lawnmower (100c, 100d) performs an arcuate movement along a cutting arc (210) and the grass-cutting disc (160) can cut grass inside the cutting arc (210); The robotic lawnmower (100) of any one of claims 1 to 8, adapted for:

10. 10. The robotic lawnmower (100) of claim 9, wherein the center of the cutting arc (210) is located along the drive axle (145).

11. 10. The robotic lawnmower (100) of claim 9, wherein the center of the cutting arc (210) is located at the center (146) of the drive axle (145).

12. 10. The robotic lawnmower of claim 9, wherein the boundary is in the form of a boundary wire that defines an operating area for the robotic lawnmower, and the control unit is adapted to stop the robotic lawnmower when the robotic lawnmower is positioned on the boundary wire, and the condition is met when a determined distance between the boundary wire and the robotic lawnmower is below a first threshold.

13. 10. The robotic lawnmower (100) of claim 9, wherein the boundary is in the shape of an object (182), the cutting arc has a nearest arc portion (211) closest to the object (182), and the condition is met if a determined distance between the object (182) and the robotic lawnmower (100) is below a second threshold.

14. The robotic lawnmower (100) of claim 13, wherein the condition is met when the robotic lawnmower (100) comes into contact with the object (182).

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