WO2024049337A1

WO2024049337A1 - Improved navigation for a robotic lawnmower

Info

Publication number: WO2024049337A1
Application number: PCT/SE2023/050613
Authority: WO
Inventors: Michel Chedid
Original assignee: Husqvarna Ab
Priority date: 2022-09-02
Filing date: 2023-06-16
Publication date: 2024-03-07
Also published as: SE545858C2; SE2251014A1

Abstract

A robotic lawnmower system (200) comprising a charging station (210) and robotic lawnmower (100) arranged to operate in an operational area (205), wherein the charging station (210) comprises a communication interface (213) comprising a first interface (213A) for establishing an internet connection and a second interface (213B) for transmitting RTK correction data to the robotic lawnmower (100) and wherein the robotic lawnmower (100) comprises a satellite navigation receiver (190) and a communication interface (115A) for receiving RTK correction data from the charging station (210), and wherein the controller (211) of the charging station (210) is configured to receive RTK correction data through an internet connection via the first interface (213A) and to transmit the RTK correction data to the robotic lawnmower (100) via the second interface (213B). And wherein the controller (110) of the robotic lawnmower (100) is configured to receive the RTK correction data from the charging station (210) via the communication interface (115A) and to determine a position for the robotic lawnmower (100) based on the received RTK correction data and the satellite navigation receiver (190).

Description

IMPROVED NAVIGATION FOR A ROBOTIC LAWNMOWER

TECHNICAL FIELD

This application relates to a robotic lawnmower, and a method for providing an improved navigation for the robotic lawnmower.

BACKGROUND

Automated or robotic lawnmowers are becoming increasingly more popular and so is the use of the robotic lawnmower in various types of operational areas.

Such operational areas, in particular for robotic lawnmowers, often include sensitive areas, such as flower beds or neighboring plots of land. Furthermore, there are many user preferences as it comes to how the lawn should be cut so that undesired patterns are not formed and/or that desired patterns are in fact formed. The requirements for an exact navigation are therefore very high.

Furthermore, as the robotic lawnmowers are in use on a daily (at least on a weekly) basis and often year-round, the running costs of the robotic lawnmowers are also subject to high requirements where even small savings accumulate to substantial amounts over time.

And, as the robotic lawnmowers are designed to be used for private lawns and should be possible to be installed by a regular person - not requiring a professional operator - the installation are also required to be simple.

Thus, there is a need for an improved manner of providing navigational functionality which has a high accuracy, is of low cost and is easy to install.

SUMMARY

It is an object of the teachings of this application to overcome or at least reduce the problems of the prior art and to provide navigational functionality which has a high accuracy, is of low cost and is easy to install.

In some aspects this is provided by a robotic lawnmower system comprising a charging station and robotic lawnmower arranged to operate in an operational area, wherein the charging station comprises a communication interface comprising a first interface for establishing an internet connection and a second interface for transmitting RTK correction data to the robotic lawnmower and wherein the robotic lawnmower comprises a satellite navigation receiver and a communication interface for receiving RTK correction data from the charging station, and wherein the controller of the charging station is configured to receive RTK correction data through an internet connection via the first interface and to transmit the RTK correction data to the robotic lawnmower via the second interface, and wherein the controller of the robotic lawnmower is configured to receive the RTK correction data from the charging station via the communication interface and to determine a position for the robotic lawnmower based on the received RTK correction data and the satellite navigation receiver.

In some embodiments the first interface of the charging station is a WiFi® interface and the controller of the charging station is further configured to establish the internet connection via the WiFi® interface.

In some embodiments the second interface of the charging station is a radio frequency interface arranged to operate at a frequency below 1 GHz and wherein the communication interface of the robotic lawnmower is configured to operate at a same frequency.

In some embodiments the second interface of the charging station is a radio frequency interface arranged to operate utilizing a LoRA modulation and wherein the communication interface of the robotic lawnmower is configured to operate at a same modulation.

In some embodiments the second interface of the charging station is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying (FSK) modulation for example a Gaussian Frequency Shift Keying (GFSK) modulation and wherein the communication interface of the robotic lawnmower is configured to operate at a same modulation.

According to some aspects the object is achieved by providing a method for use in a robotic lawnmower system comprising a charging station and robotic lawnmower arranged to operate in an operational area, wherein the charging station comprises a communication interface comprising a first interface for establishing an internet connection and a second interface for transmitting RTK correction data to the robotic lawnmower and wherein the robotic lawnmower comprises a satellite navigation receiver and a communication interface for receiving RTK correction data from the charging station, and wherein the method comprises the controller of the charging station receiving RTK correction data through an internet connection via the first interface and transmitting the RTK correction data to the robotic lawnmower via the second interface, and wherein the method further comprises the controller of the robotic lawnmower receiving the RTK correction data from the charging station via the communication interface and determining a position for the robotic lawnmower based on the received RTK correction data and the satellite navigation receiver.

According to some aspects the object is achieved by providing a charging station comprising a first interface for establishing an internet connection and a second interface for transmitting RTK correction data to a robotic lawnmower comprising a satellite navigation receiver, and wherein the controller of the charging station is configured to receive RTK correction data through an internet connection via the first interface and to transmit the RTK correction data to the robotic lawnmower via the second interface.

In some embodiments the first interface is a WiFi® interface and the controller is further configured to establish the internet connection via the WiFi® interface.

In some embodiments the second interface is a radio frequency interface arranged to operate at a frequency below 1 GHz.

In some embodiments the second interface charging station is a radio frequency interface arranged to operate utilizing a LoRA modulation.

In some embodiments the second interface charging station is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying (FSK) modulation for example a Gaussian Frequency Shift Keying (GFSK) modulation.

According to some aspects the object is achieved by providing a method for use in a charging station comprising a first interface for establishing an internet connection and a second interface for transmitting RTK correction data to a robotic lawnmower comprising a satellite navigation receiver, and wherein the method comprises receiving RTK correction data through an internet connection via the first interface and transmitting the RTK correction data to the robotic lawnmower via the second interface. According to some aspects the object is achieved by providing a robotic lawnmower comprising a satellite navigation receiver and a communication interface for receiving RTK correction data from a charging station, wherein the controller of the robotic lawnmower is configured to receive the RTK correction data from the charging station via the communication interface and to determine a position for the robotic lawnmower based on the received RTK correction data and the satellite navigation receiver.

In some embodiments the communication interface is a radio frequency interface arranged to operate at a frequency below 1 GHz.

In some embodiments the communication interface is a radio frequency interface arranged to operate utilizing a LoRA modulation.

In some embodiments the communication interface is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying (FSK) modulation for example a Gaussian Frequency Shift Keying (GFSK) modulation.

According to some aspects the object is achieved by providing a method for use in a robotic lawnmower comprising a satellite navigation receiver and a communication interface for receiving RTK correction data from a charging station, wherein method comprises receiving the RTK correction data from the charging station via the communication interface and determining a position for the robotic lawnmower based on the received RTK correction data and the satellite navigation receiver.

Further embodiments and aspects are as in the attached patent claims and as discussed in the detailed description.

Other features and advantages of the disclosed embodiments will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings. Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [element, device, component, means, step, etc.]" are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in further detail under reference to the accompanying drawings in which:

Figure 1 shows a schematic view of the components of an example of a robotic lawnmower according to some example embodiments of the teachings herein;

Figure 2 shows a schematic view of a robotic lawnmower system according to some example embodiments of the teachings herein;

Figure 3 shows a schematic view of a charging station according to some example embodiments of the teachings herein; and

Figure 4 shows a corresponding flowchart for a method according to some example embodiments of the teachings herein.

DETAILED DESCRIPTION

The disclosed embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like reference numbers refer to like elements throughout.

It should be noted that even though the description given herein will be focused on robotic lawnmowers, the teachings herein may also be applied to, robotic ball collectors, robotic mine sweepers, robotic farming equipment, or other robotic lawnmowers.

Figure 1 shows a schematic overview of a robotic lawnmower 100. The robotic lawnmower 100 may be a multi -chassis type or a mono-chassis type (as in figure 1). A multi -chassis type comprises more than one main body parts that are movable with respect to one another. A mono-chassis type comprises only one main body part.

It should be noted that robotic lawnmower may be of different sizes, where the size ranges from merely a few decimetres for small garden robots, to even more than 1 meter for large robots arranged to service for example airfields.

It should be noted that even though the description herein is focussed on the example of a robotic lawnmower, the teachings may equally be applied to other types of robotic work tools, such as robotic watering tools, robotic golfball collectors, and robotic mulchers to mention a few examples. It should be noted also that even if the description herein is focussed on the robotic lawnmower, a skilled person would be able to implement the teachings herein, having taken part of them, in another type of robotic work tool - especially for gardening purposes - as many components are shared between such robotic work tools.

It should also be noted that the robotic lawnmower is a self-propelled robotic lawnmower, capable of autonomous navigation within an operational area, where the robotic lawnmower propels itself across or around the operational area in a pattern (random or predetermined).

The robotic lawnmower 100, exemplified as a robotic lawnmower 100, has a main body part 140, possibly comprising a chassis 140 and an outer shell 140A, and a plurality of wheels 130 (in this example four wheels 130, but other number of wheels are also possible, such as three or six).

The main body part 140 substantially houses all components of the robotic lawnmower 100. At least some of the wheels 130 are drivably connected to at least one electric motor 155 powered by a battery 150. It should be noted that even if the description herein is focused on electric motors, combustion engines may alternatively be used, possibly in combination with an electric motor. In the example of figure 1, each of the wheels 130 is connected to a common or to a respective electric motor 155 for driving the wheels 130 to navigate the robotic lawnmower 100 in different manners. The wheels, the motor 155 and possibly the battery 150 are thus examples of components making up a propulsion device. By controlling the motors 155, the propulsion device may be controlled to propel the robotic lawnmower 100 in a desired manner, and the propulsion device will therefore be seen as synonymous with the motor(s) 150. It should be noted that wheels 130 driven by electric motors is only one example of a propulsion system and other variants are possible such as caterpillar tracks.

The robotic lawnmower 100 also comprises one or more charging connectors 165 for engaging corresponding charging connectors of a charging station (not shown in figure 1 but referenced 210 and 216 respectively in figures 2 and 3). The robotic lawnmower 100 also comprises a work tool 160, which in the example of the robotic lawnmower 100 is a grass cutting device 160, such as a rotating blade 160/2 driven by a cutter motor 160/1. In embodiments where the robotic work tool 100 is exemplified as an automatic grinder, the work tool 160 is a rotating grinding disc.

The robotic lawnmower 100 also comprises a controller 110 and a computer readable storage medium or memory 120. The controller 110 may be implemented using instructions that enable hardware functionality, for example, by using executable computer program instructions in a general -purpose or special-purpose processor that may be stored on the memory 120 to be executed by such a processor. The controller 110 is configured to read instructions from the memory 120 and execute these instructions to control the operation of the robotic lawnmower 100 including, but not being limited to, the propulsion and navigation of the robotic lawnmower.

The controller 110 in combination with the electric motor 155 and the wheels 130 forms the base of a navigation system (possibly comprising further components) for the robotic lawnmower, enabling it to be self-propelled as discussed.

The controller 110 may be implemented using any suitable, available processor or Programmable Logic Circuit (PLC). The memory 120 may be implemented using any commonly known technology for computer-readable memories such as ROM, FLASH, DDR, or some other memory technology.

The robotic lawnmower 100 is further arranged with a wireless communication interface 115 for communicating with other devices, such as a server, a personal computer, a smartphone, the charging station, and/or other robotic lawnmowers. Examples of such wireless communication devices are Bluetooth®, WiFi® (IEEE802.1 lb), Global System Mobile (GSM) and LTE (Long Term Evolution), to name a few. The robotic lawnmower 100 may be arranged to communicate with a user equipment (not shown but will be regarded as being an example of a server, as an example of a connected device) as discussed in relation to figure 2 below for providing information regarding status, location, and progress of operation to the user equipment as well as receiving commands or settings from the user equipment. Specifically, the communication interface 115 includes an interface 115A for communication with the charging station via a radio frequency interface 115A, specifically to receive RTK correction data from the charging station 210.

In some embodiments the communication interface 115 is arranged - via the radio frequency interface 115A - to operate at a frequency below 1 GHz. Examples of such frequencies are any frequency in the range 500 MHz-999 MHz or in the range 400 MHz-999 MHz, for example the 868 MHz band (863-870 MHz), 433 MHz band (433.050 MHz to 434.790 MHz, i.e. LPD433) or 915 MHz band (902 - 920 MHz).

In some such embodiments the communication interface 115 is arranged - via the radio frequency interface 115A - to operate utilizing a modulation technique such as LoRA. LoRa is a wireless modulation technique derived from Chirp Spread Spectrum (CSS) technology. In general, LoRA encodes information on radio waves (868MHz, 915MHz and 2.4GHz frequency bands) using chirp pulses - similar to the way dolphins and bats communicate! LoRa modulated transmission is robust against disturbances and can be received across great distances.

In some alternative such embodiments the communication interface 115 is arranged - via the radio frequency interface 115A - to operate utilizing a modulation technique such as Frequency Shift Keying (FSK), and in particular Gaussian Frequency Shift Keying (GFSK). Gaussian frequency-shift keying (GFSK) is a type of Frequency Shift Keying (FSK) modulation which uses a Gaussian filter to shape the pulses before they are modulated. This reduces the spectral bandwidth and out-of-band spectrum, to meet adjacent-channel power rejection requirements.

In some such embodiments the communication interface 115 is arranged - via the radio frequency interface 115A - to operate utilizing a Frequency Hopping Spread Spectrum (FHSS) spreading technology. Frequency Hopping Spread Spectrum is a method of transmitting radio signals by rapidly changing the carrier frequency among many frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter (charging station) and receiver (robotic work tool).

In some such alternative or additional embodiments, the communication interface 115 is arranged - via the radio frequency interface 115A - to operate utilizing an encryption scheme, such as Advanced Encryption Standard (AES). The AES is a symmetric block cipher that the U.S. government selects to protect classified data. In some such alternative or additional embodiments, the communication interface 115 is arranged - via the radio frequency interface 115A - to operate the AES in electronic code book mode (ECB) or in counter (CTR) mode.

This allows multiple robotic work tools to operate in close proximity without overhearing information intended for other robotic work tools.

The robotic lawnmower 100 comprises a satellite signal navigation receiver 190 configured to provide navigational information (such as position) based on receiving one or more signals from a satellite - possibly in combination with receiving a signal from a base station. In some embodiments the satellite navigation receiver 190 is a Real-Time Kinetics (RTK) receiver. In some embodiments the satellite navigation receiver 190 is a Global Positioning System (GPS) receiver. In some embodiments the satellite navigation receiver 190 is a Global Navigation Satellite System (GNSS) receiver. This enables the robotic lawnmower to operate in an operational area bounded by a virtual border (not shown explicitly in figure 2 but deemed to be included in the boundary 220).

For enabling the robotic lawnmower 100 to navigate with reference to a wire, such as a boundary wire or a guide wire, emitting a magnetic field caused by a control signal transmitted through the wire, the robotic lawnmower 100 is, in some embodiments, configured to have at least one magnetic field sensor 170 arranged to detect the magnetic field and for detecting the wire and/or for receiving (and possibly also sending) information to/from a signal generator. In some embodiments, such a magnetic boundary is used to provide a border (not shown explicitly in figure 2 but deemed to be included in the boundary 220) enclosing an operational area (referenced 205 in figure 2). Such navigation may be supplemental to the navigation based on the RTK receiver 190.

The robotic lawnmower 100 may also in some embodiments comprise deduced reckoning sensors 180. The deduced reckoning sensors may be odometers, accelerometers or other deduced reckoning sensors. Such deduced-reckoning navigation may be supplemental to the navigation based on the RTK receiver 190. The robotic lawnmower 100 is in some embodiments arranged to operate according to a map application 120 A representing one or more operational areas (and possibly the surroundings of the operational area(s)) as well as features of the operational area(s) stored in the memory 120 of the robotic lawnmower 100. In some embodiments, the map is also or alternatively stored in the memory of a server (referenced 240 in figure 2). The map application may be generated or supplemented as the robotic lawnmower 100 operates or otherwise moves around in the operational area. In some embodiments, the map application is downloaded, possibly from the server. In some embodiments, the map application also includes one or more transport areas (not shown). The robotic lawnmower 100 is arranged to navigate according to the map based on the RTK receiver 190, possibly in combination with the deduced reckoning sensors 180 and/or the magnetic field sensor(s) 170.

The robotic lawnmower also comprises a user interface 185 for receiving commands and/or settings from an operator or user. In some embodiments the user interface 185 comprises a physical interface such as a display and/or one or more buttons (possibly virtual keys implemented on the display). In some embodiments the user interface 185 comprises remote interface such as a connection to a cellular user equipment such as a tablet computer and/or a smartphone (referenced 250 in figure 2) via the communication interface 115. In some embodiments the user interface 185 comprises both a physical interface as well as a remote interface.

Figure 2 shows a robotic lawnmower system 200 in some embodiments. The schematic view is not to scale. The robotic lawnmower system 200 comprises one or more robotic lawnmowers 100 according to the teachings herein arranged to operate in one or more operational areas 205 bounded by a boundary 220. It should be noted that the operational area 205 shown in figure 2 is simplified for illustrative purposes.

The view of the operational area 205 is also intended to be an illustration or graphical representation of the map application 120A discussed in the above.

As discussed in relation to figure 1 the robotic lawnmower system may be a robotic lawnmower system or a system comprising a combination of one or more robotic lawnmowers, and other robotic work tools. As is shown in figure 2 there may be obstacles such as houses, structures, trees to mention a few examples in the operational area 205. In figure 2 such obstacles are indicated and referenced H (as in house). There may also be one or more irregularities in the surface of the operational area, which are exemplified in figure 2 as a house H, a slope S, a tree T and a flower bed FB.

A server 240 is shown as an optional connected device for the robotic lawnmower 100 to communicate with - possibly for receiving maps or map updates. The server 240 comprises a controller 240A for controlling the operation of the server 240, a memory 240B for storing instructions and data relating to the operation of the server 240 and a communication interface 240C for enabling the server 240 to communicate with other entities, such as the robotic lawnmower 100, and/or a User Equipment such as a mobile phone. The controller, the memory and the communication interface may be of similar types as discussed in relation to figure 1 for the robotic lawnmower 100. It should be noted that any processing may be done in any, some or all of the controller 110 of the robotic lawnmower 100 and/or the controller 240A of the server 240 and that the processing may also be done partially in one controller 110/240A for supplemental processing in the other controller 110/240A. This is indicated in figure 2 in that a dashed arrow is shown between the server 240and the robotic lawnmower 100 for indicating that information may be passed freely between them for (partial) processing.

The robotic lawnmower system 200 also comprises a charging station 210 and figure 3 shows a schematic view of such a charging station 210. The charging station 210 comprises a power source 215, such as an electric charger supplied with electric current from a remote source (not shown), and charging connector(s) 216 for engaging corresponding charging connectors 165 on a robotic lawnmower 100. In some embodiments, the charging station comprises a bottom plate 217 for the robotic lawnmower 100 to navigate onto when attempting to charge.

The charging station comprises a controller 211 and a memory 212 for storing data and instructions that when loaded into the controller 211 enables the controller 211 to control the general operation of the charging station 210.

In some embodiments where the robotic lawnmower 100 is arranged to operate according to a boundary wire 220 emitting a magnetic field, the charging station 210 also comprises a signal generator 214 arranged to generate a control signal and to transmit the control signal through the boundary wire, thereby generating the magnetic field that is to be sensed by the robotic lawnmower 100.

The charging station also comprises a communication interface 213. The communication interface 213 comprises a first interface 213 A for establishing an internet connection and a second interface 213B for establishing a connection with the robotic lawnmower 100.

As is known, Real-time kinematic positioning (RTK) is the application of surveying or navigation by correcting for common errors in current satellite navigation (GNSS) systems. It uses measurements of the phase of the signal's carrier wave in addition to the information content of the signal and relies on a single reference station or interpolated virtual station to provide real-time corrections, providing up to centimetre-level accuracy. Using a RTK navigation method will thus provide a highly accurate navigation which fulfils the requirements from most users.

A vehicle navigation based on a RTK receiver 190 is thus based on the RTK receiver 190 receiving satellite navigation data and in addition to this the RTK receiver 190 (or at least the vehicle) also receives RTK correction data from a beacon or base station. However, such base stations are sometimes considered to be difficult to install as the base station needs to be carefully placed so that it is not shadowed. The base stations are also relatively expensive adding to the initial cost of the robotic lawnmower system 200.

In order to operate the robotic lawnmower 100 based on RTK navigation without utilizing such a base station enables for the robotic lawnmower system lOOto be easier to install and lowers the cost of the robotic lawnmower system 200. This is possible by receiving the RTK correction data from a (third part) internet service. This can be achieved by enabling the robotic lawnmower 100 to connect to a server, such as server 240, directly through the communication interface 115, especially when the communication interface includes a cellular component.

However, as the RTK correction data is needed on a more or less continuous basis, the data that needs to be downloaded via the cellular communication interface is not negligible and the data traffic amounts and the costs associated over time. Furthermore, as the operational area 205 may include high structures such as trees and houses, the cellular communication interface may not always have a satisfactory reception and the robotic lawnmower 100 will thus not be able to operate with high accuracy in the whole operational area 205.

The inventors have realized that the internet connection may be established indirectly in a very simple - yet insightful - manner by utilizing the charging station 210 as a proxy for the robotic lawnmower 100. To achieve this the charging station is - as is discussed int eh above - arranged with a communication interface 213 comprising two interfaces; a first interface 213 A for establishing an internet connection and a second interface 213B for establishing a connection with the robotic lawnmower 100. The charging station 210 is thereby configured to receive RTK correction data via the first interface 213 A through the internet connection. As the charging station is not mobile, the internet connection may be established via a non-cellular interface, for example a fiber-based connection, where the costs are not associated with the amount of data that is downloaded. In some embodiments, the first interface 213A is based on a WiFi® connection thereby enabling the charging station 210 to establish the internet connection via the first interface 213 A connecting with an internet gateway 260 for example in the house of the user. The charging station is thus enabled to establish the internet connection via the common household WiFi® network. This thus enables a substantially free download of the RTK correction data, at least as seen to the amount of data downloaded.

The inventors have realized that as the Wifi® network has a limited range and as it is sensitive to being blocked, the robotic lawnmower 100 will in most operational areas 205 not be able to receive the RTK correction data via a WiFi connection, not even if the Charging station 210 acts as a relay station. To enable the RTK data to be transmitted successfully although out the operational area 205, the inventors have arranged the charging station 210 also with the second interface 213B which is used to transmit the RTK correction data to the robotic lawnmower 100. The second interface 213B - as discussed in the above - a radio frequency interface. The radio frequency interface of the second interface 213B is arranged to transmit over a long range and without being easily blocked. This is achieved in some embodiments by the radio frequency interface 213B being a subGHz interface (i.e. a radio frequency interface arranged to transmit at frequencies lower than 1 GHz) and in some embodiments by the radio frequency interface 213B being arranged to transmit utilizing LoRA modulation. In some embodiments the radio frequency interface 213B is a SubGHz interface utilizing LoRA modulation. In some embodiments the radio frequency interface 213B is a long-range Bluetooth® interface. In some embodiments the radio frequency interface 213B is a Frequency Shift Keying (FSK) interface such as a Gaussian Frequency Shift Keying (GFSK) interface.

As would be understood buy a skilled person, the communication interface 115 (especially the portion 115A) will be arranged to communicate according to the same technology as the second interface 213B of the charging station 210.

Returning to figure 2, the charging station 210 thus receives the RTK correction data (possibly from the server 240) via the first interface 213 A. In some embodiments where the first interface 213 A is a WiFi® interface, the data is received through an internet gateway 260 (such as a WiFi® router or hotspot). The data is thus received without incurring any additional data traffic costs.

The charging station 210 then forwards the RTK correction data to the robotic lawnmower 100 via the second interface 213B being a long-range Radio Frequency interface. The data will thus be provided safely to the robotic lawnmower 100 in most operational areas 205.

The inventors are thus providing a simple - yet highly effective - manner of providing high accuracy navigation without needing to install an expensive base station, without incurring high data traffic costs and while enabling the high accuracy navigation in all (or at least most) portions of operational areas 205.

Figure 4 shows a flowchart for a general method according to herein. The method is for use in a robotic lawnmower as in figure 1, in a charging station as in figure 3 and in a robotic lawnmower system 200 as in figure 2 in a manner as discussed above in relation to figures 1, 2, and 3.

The method comprises a controller of the charging station 210 receiving 410 RTK correction data through an internet connection via the first interface 213 A and transmitting 420 the RTK correction data to the robotic lawnmower 100 via the second interface 213B. The method also comprises the controller 110 of the robotic lawnmower 100 receiving 430 the RTK correction data from the charging station 210 via the communication interface 115A and determining 440 a position for the robotic lawnmower 100 based on the received RTK correction data and the satellite navigation receiver 190.

Claims

1. A robotic lawnmower system (200) comprising a charging station (210) and robotic lawnmower (100) arranged to operate in an operational area (205), wherein the charging station (210) comprises a communication interface (213) comprising a first interface (213 A) for establishing an internet connection and a second interface (213B) for transmitting RTK correction data to the robotic lawnmower (100) and wherein the robotic lawnmower (100) comprises a satellite navigation receiver (190) and a communication interface (115 A) for receiving RTK correction data from the charging station (210), and wherein the controller (211) of the charging station (210) is configured to receive RTK correction data through an internet connection via the first interface

(213 A) and to transmit the RTK correction data to the robotic lawnmower (100) via the second interface (213B), and wherein the controller (110) of the robotic lawnmower (100) is configured to receive the RTK correction data from the charging station (210) via the communication interface (115 A) and to determine a position for the robotic lawnmower (100) based on the received RTK correction data and the satellite navigation receiver (190).

2. The robotic lawnmower system (200) according to claim 1, wherein the first interface (213 A) of the charging station (210) is a WiFi® interface and the controller (211) of the charging station (210) is further configured to establish the internet connection via the WiFi® interface (213 A).

3. The robotic lawnmower system (200) according to claim 1 or 2, wherein the second interface (213B) of the charging station (210) is a radio frequency interface arranged to operate at a frequency below 1 GHz and wherein the communication interface (115A) of the robotic lawnmower (100) is configured to operate at a same frequency.

4. The robotic lawnmower system (200) according to any preceding claim, wherein the second interface (213B) of the charging station (210) is a radio frequency interface arranged to operate utilizing a LoRA modulation and wherein the communication interface (115A) of the robotic lawnmower (100) is configured to operate at a same modulation.

5. The robotic lawnmower system (200) according to any of claims 1 to 3, wherein the second interface (213B) of the charging station (210) is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying modulation and wherein the communication interface (115 A) of the robotic lawnmower (100) is configured to operate at a same modulation.

6. A method for use in a robotic lawnmower system (200) comprising a charging station (210) and robotic lawnmower (100) arranged to operate in an operational area (205), wherein the charging station (210) comprises a communication interface (213) comprising a first interface (213 A) for establishing an internet connection and a second interface (213B) for transmitting RTK correction data to the robotic lawnmower (100) and wherein the robotic lawnmower (100) comprises a satellite navigation receiver (190) and a communication interface (115A) for receiving RTK correction data from the charging station (210), and wherein the method comprises the controller (211) of the charging station (210) receiving RTK correction data through an internet connection via the first interface (213 A) and transmitting the RTK correction data to the robotic lawnmower (100) via the second interface (213B), and wherein the method further comprises the controller (110) of the robotic lawnmower (100) receiving the RTK correction data from the charging station (210) via the communication interface (115 A) and determining a position for the robotic lawnmower (100) based on the received RTK correction data and the satellite navigation receiver (190).

7. A charging station (210) comprising a first interface (213 A) for establishing an internet connection and a second interface (213B) for transmitting RTK correction data to a robotic lawnmower (100) comprising a satellite navigation receiver (190), and wherein the controller (211) of the charging station (210) is configured to receive RTK correction data through an internet connection via the first interface (213 A) and to transmit the RTK correction data to the robotic lawnmower (100) via the second interface (213B).

8. The charging station (210) according to claim 7, wherein the first interface (213A) is a WiFi® interface and the controller (211) is further configured to establish the internet connection via the WiFi® interface (213 A).

9. The charging station (210) according to claim 7 or 8, wherein the second interface (213B) is a radio frequency interface arranged to operate at a frequency below 1 GHz.

10. The charging station (210) according to any of claims 7, 8 or 9, wherein the second interface (213B) charging station (210) is a radio frequency interface arranged to operate utilizing a LoRA modulation.

11. The charging station (210) according to any of claims 7, 8 or 9, wherein the second interface (213B) charging station (210) is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying modulation.

12. A method for use in a charging station (210) comprising a first interface (213A) for establishing an internet connection and a second interface (213B) for transmitting RTK correction data to a robotic lawnmower (100) comprising a satellite navigation receiver (190), and wherein the method comprises receiving RTK correction data through an internet connection via the first interface (213 A) and transmitting the RTK correction data to the robotic lawnmower (100) via the second interface (213B).

13. A robotic lawnmower (100) comprising a satellite navigation receiver (190) and a communication interface (115 A) for receiving RTK correction data from a charging station (210), wherein the controller (110) of the robotic lawnmower (100) is configured to receive the RTK correction data from the charging station (210) via the communication interface (115 A) and to determine a position for the robotic lawnmower (100) based on the received RTK correction data and the satellite navigation receiver (190).

14. The robotic lawnmower (100) according to claim 12, wherein the communication interface (115 A) is a radio frequency interface arranged to operate at a frequency below 1 GHz.

15. The robotic lawnmower (100) according to claim 13 or 14, wherein the communication interface (115 A) is a radio frequency interface arranged to operate utilizing a LoRA modulation.

16. The robotic lawnmower (100) according to claim 13 or 14, wherein the communication interface (115 A) is a radio frequency interface arranged to operate utilizing a Frequency Shift Keying modulation.

17. A method for use in a robotic lawnmower (100) comprising a satellite navigation receiver (190) and a communication interface (115A) for receiving RTK correction data from a charging station (210), wherein method comprises receiving the RTK correction data from the charging station (210) via the communication interface (115 A) and determining a position for the robotic lawnmower (100) based on the received RTK correction data and the satellite navigation receiver (190).