WO2023179881A1

WO2023179881A1 - Obstacle detecting arrangement in a robotic cleaning device

Info

Publication number: WO2023179881A1
Application number: PCT/EP2022/058025
Authority: WO
Inventors: Magnus WENNERSTRÖM
Original assignee: Aktiebolaget Electrolux
Priority date: 2022-03-25
Filing date: 2022-03-25
Publication date: 2023-09-28

Abstract

The present disclosure relates to an obstacle detecting arrangement (200) in a robotic cleaning device (100).In an aspect, an obstacle detecting arrangement (200) in a robotic cleaning device (100) is provided. The arrangement comprises a light detecting sensor (123) configured to detect obstacles in an environment in which the robotic cleaning device (100) moves, at least a first structured light source (127) configured to illuminate the obstacles to be detected in a line of sight of the light detecting sensor (123) and a common printed circuit board (129) to which the light detecting sensor (123) and said first structured light source (127) are fixedly mounted.

Description

OBSTACLE DETECTING ARRANGEMENT IN A ROBOTIC CLEANING DEVICE

TECHNICAL FIELD

[0001] The present disclosure relates to an obstacle detecting arrangement in a robotic cleaning device.

BACKGROUND

[0002] In many fields of technology, it is desirable to use robots with an autonomous behaviour such that they freely can move around a space without colliding with possible obstacles.

[0003] Robotic vacuum cleaners are known in the art, which are equipped with drive means in the form of a motor for moving the cleaner across a surface to be cleaned. The robotic vacuum cleaners are further equipped with intelligence in the form of microprocessor(s) and navigation means for causing an autonomous behaviour such that the robotic vacuum cleaners freely can move around and clean a surface in the form of e.g. a floor. Thus, these prior art robotic vacuum cleaners have the capability of more or less autonomously moving across, and vacuum-cleaning, a room without colliding with obstacles located in the room, such as furniture, pets, walls, doors, etc.

[0004] Commonly, robotic vacuum cleaners comprise one or more structured light sources, such as e.g. lasers, arranged to illuminate obstacles to be detected by a camera in order for the cleaner to be capable of navigating a surface and avoiding collision with any encountered obstacles.

[0005] To attain a precise navigation, it is important that the positions of the lasers are maintained relative the camera, since also small deviations cause navigation problems and unwanted errors. Deviations can be caused by temperature variations, component handling during assembly, mounting imperfections, etc.

SUMMARY

[0006] An objective is to solve, or at least mitigate, this problem in the art and to provide and improved obstacle detection arrangement of a robotic cleaning device. [0007] This objective is attained in an aspect by an obstacle detecting arrangement in a robotic cleaning device. The arrangement comprises a light detecting sensor configured to detect obstacles in an environment in which the robotic cleaning device moves, at least a first structured light source configured to illuminate the obstacles to be detected in a line of sight of the light detecting sensor and a common printed circuit board to which the light detecting sensor and the first structured light source are fixedly mounted.

[0008] Advantageously, by fixedly arranging the structured light source to the common printed circuit board in relation to the light detecting sensor, the position of the structured light source is firmly maintained relatively to the light detecting sensor and a firm mechanical stability is attained.

[0009] In an embodiment, the obstacle detecting arrangement further comprises at least a second structured light source configured to illuminate the obstacles to be detected in the line of sight of the light detecting sensor, the second structured light source being symmetrically arranged on an opposite side of the light detecting sensor with respect to the first structured light source and mounted fixedly to the common printed circuit board.

[0010] In an embodiment, the obstacle detecting arrangement further comprises a sensor printed circuit board to which the light detecting sensor further is mounted.

[0011] In an embodiment, the obstacle detecting arrangement further comprises connectors being attached to the sensor printed circuit board for transporting data to a controller of the robotic cleaning device.

[0012] In an embodiment, the sensor printed circuit board is configured to be mounted with one end abutting the common printed circuit board.

[0013] In an embodiment, the light detecting sensor, the first structured light source and the second structured light source are configured to be fixedly mounted to the common printed circuit board by means of fasteners, soldering or welding.

[0014] In an embodiment, the light detecting sensor comprises a camera.

[0015] In an embodiment, the first structured light source and the second structured light source each comprises a laser. [0016] In an embodiment, the obstacle detecting arrangement further comprises a support component mounted to the common printed circuit board.

[0017] In an embodiment, a robotic cleaning device is provided comprising the obstacle detecting arrangement according to any one of the above-mentioned embodiments.

[0018] 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, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, 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

[0019] Aspects and embodiments are now described, by way of example, with reference to the accompanying drawings, in which:

[0020] Figure 1 shows a robotic cleaning device according to an embodiment in a bottom view;

[0021] Figure 2 shows the robotic cleaning device of Figure 1 in a front view; and

[0022] Figure 3 shows a side perspective view of an obstacle detecting arrangement according to an embodiment:

[0023] Figures 4-6 show the obstacle detecting arrangement according to an embodiment in a top view, a front view and a bottom view, respectively;

[0024] Figure 7 illustrates a structured light source in the form of a line laser; and

[0025] Figure 8 illustrates a light detecting sensor in the form of a camera.

DETAILED DESCRIPTION

[0026] The aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments are shown. [0027] These aspects may, however, be embodied in many different forms and should not be construed as limiting; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and to fully convey the scope of all aspects to those skilled in the art. Like numbers refer to like elements throughout the description.

[0028] The disclosure relates to an obstacle detecting arrangement in a robotic cleaning device, or in other words, an automatic, self-propelled machine for cleaning a surface, e.g. a robotic vacuum cleaner, a robotic sweeper or a robotic floor washer. Such robotic cleaning device can be mains-operated and have a cord, be battery- operated or use any other kind of suitable energy source, for example solar energy.

[0029] Even though it is envisaged that embodiments of the obstacle detecting arrangement may be implemented in a variety of appropriate robotic cleaning devices being equipped with sufficient processing intelligence, Figure 1 shows a robotic cleaning device 100 according to an embodiment in a bottom view, i.e. the underside of the robotic cleaning device is shown. The arrow indicates the forward direction of the robotic cleaning device 100 being illustrated in the form of a robotic vacuum cleaner.

[0030] The robotic vacuum cleaner 100 comprises a main body 111 housing components such as a propulsion system comprising driving means in the form of two electric wheel motors 114, 115 for enabling movement of the driving wheels 112, 113 such that the robotic vacuum cleaner 100 can be moved over a surface to be cleaned. Each wheel motor 114, 115 is capable of controlling the respective driving wheel 112, 113 to rotate independently of each other in order to move the robotic vacuum cleaner 100 across the surface to be cleaned. A number of different driving wheel arrangements, as well as various wheel motor arrangements, can be envisaged. It should be noted that the robotic vacuum cleaner 100 may have any appropriate shape, such as a device having a more traditional circular-shaped main body, or a triangular-shaped main body. As an alternative, a track propulsion system may be used or even a hovercraft propulsion system. The propulsion system may further be arranged to cause the robotic vacuum cleaner 100 to perform any one or more of a yaw, pitch, translation or roll movement.

[0031] A controller 116 such as a microprocessor controls the wheel motors 114, 115 to rotate the driving wheels 112, 113 as required in view of information received from the obstacle detecting arrangement (not shown in Figure 1) for detecting obstacles in the form of walls, floor lamps, table legs, around which the robotic cleaning device 100 must navigate. The obstacle detecting arrangement maybe embodied in the form of a 3D sensor system registering its surroundings, implemented by means of e.g. a camera in combination with one or more lasers, for detecting obstacles and communicating information about any detected obstacle to the microprocessor 116. The microprocessor 116 communicates with the wheel motors 114, 115 to control movement of the wheels 112, 113 in accordance with information provided by the obstacle detecting device such that the robotic vacuum cleaner 100 can move as desired across the surface to be cleaned.

[0032] Moreover, the main body 111 of the robotic vacuum cleaner 100 comprises a suction fan 120 creating an air flow for transporting debris to a dust bag or cyclone arrangement (not shown) housed in the main body via the opening 118 in the bottom side of the main body 111. The suction fan 120 is driven by a fan motor 121 communicatively connected to the controller 116 from which the fan motor 121 receives instructions for controlling the suction fan 120. The main body 111 may further be arranged with one or more rotating side brushes 122 adjacent to the opening 118.

[0033] Further, the main body 111 may optionally be arranged with a cleaning member 117 for removing debris and dust from the surface to be cleaned in the form of a rotatable brush roll arranged in an opening 118 at the bottom of the robotic cleaner 100. Thus, the rotatable brush roll 117 is arranged along a horizontal axis in the opening 118 to enhance the dust and debris collecting properties of the cleaning device 100. In order to rotate the brush roll 117, a brush roll motor 119 is operatively coupled to the brush roll to control its rotation in line with instructions received from the controller 116.

[0034] With further reference to Figure 1, the controller/ processing unit 116 embodied in the form of one or more microprocessors is arranged to execute a computer program 125 downloaded to a suitable storage medium 126 associated with the microprocessor, such as a Random Access Memory (RAM), a Flash memory or a hard disk drive. The controller 116 is arranged to carry out navigation when the appropriate computer program 125 comprising computer-executable instructions is downloaded to the storage medium 126 and executed by the controller 116. The storage medium 126 may also be a computer program product comprising the computer program 125. Alternatively, the computer program 125 may be transferred to the storage medium 126 by means of a suitable computer program product, such as a digital versatile disc (DVD), compact disc (CD) or a memory stick. As a further alternative, the computer program 125 maybe downloaded to the storage medium 126 over a wired or wireless network. The controller 116 may alternatively be embodied in the form of a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), etc.

[0035] Figure 2 shows a front view of the robotic vacuum cleaner 100 of Figure 1 in an embodiment illustrating the previously mentioned obstacle detecting arrangement in the form of a 3D sensor system comprising at least one light detecting sensor in the form of a camera 123 and a first and a second structured light source, e.g. line lasers 127, 128, which maybe horizontally or vertically oriented. It is noted that the obstacle detecting arrangement in an alternative embodiment may comprise a single structured light source 127 or 128. Further shown is the controller 116, the main body 111, and the driving wheels 112, 113.

[0036] The controller 116 is operatively coupled to the camera 123 for recording images of a vicinity of the robotic vacuum cleaner 100. The first and second line lasers 127, 128 may preferably be vertical line lasers and are arranged lateral of the camera 123. The camera 123 is controlled by the controller 116 to capture and record a plurality of images per second. Data from the images is extracted by the controller 116 and the data is typically saved in the memory 126 along with the computer program 125, and is utilized to form a representation of an environment in which the robotic vacuum cleaner 100 moves.

[0037] The first and second line laser 127, 128 are configured to scan, preferably in a vertical orientation, the vicinity of the robotic vacuum cleaner 100, normally in the direction of movement of the robotic cleaning device 100. The first and second line lasers 127, 128 are configured to send out laser beams, which illuminate furniture, walls and other objects of e.g. a room to be cleaned. The camera 123 is controlled by the controller 116 to capture and record images from which the controller 116 creates a representation or layout of the surroundings that the robotic vacuum cleaner 100 is operating in, by extracting features from the images and by measuring the distance covered by the robotic vacuum cleaner 100, while the robotic vacuum cleaner 100 is moving across the surface to be cleaned.

[0038] Thus, the controller 116 derives positional data of the robotic vacuum cleaner 100 with respect to the surface to be cleaned from the recorded images, generates a 3D representation of the surroundings from the derived positional data and controls the driving motors 114, 115 to move the robotic vacuum cleaner across the surface to be cleaned in accordance with the generated 3D representation and navigation information supplied to the robotic vacuum cleaner 100 such that the surface to be cleaned can be navigated by taking into account the generated 3D representation. Alternatively, it would be possible to use 3D sensors utilizing time of flight measurements of an image being completely illuminated. With such a time of flight 3D sensor, the distance in a captured image would be determined for each pixel and distances to detected objects maybe determined in line with the above.

[0039] As previously mentioned, and as can be concluded from the above description, to attain a precise navigation, it is important that the positions of the lasers 127, 128 are maintained relative the camera 123, since also small deviations cause navigation problems and unwanted errors. Deviations can be caused by temperature variations, component handling during assembly, mounting imperfections, etc. Further, the relative positions may change even after calibration of the lasers with respect to the camera due to e.g. vibrations, deformations in for instance plastic components, shocks, etc.

[0040] Figure 3 shows a side perspective view of an obstacle detecting arrangement 200 according to an embodiment as described with reference to Figure 2.

[0041] As shown, the first line laser 127 and the second line laser 128 are configured to illuminate obstacles to be detected in a line of sight of the camera 123. As mentioned, it maybe envisaged that the obstacle detecting arrangement 200 utilizes a single line laser.

[0042] In this particular embodiment and as previously shown in Figure 2, the second line laser 128 is symmetrically arranged on an opposite side of the camera 123 with respect to the first line laser 127 and mounted fixedly to a common printed circuit board (PCB) 129. [0043] Advantageously, by fixedly arranging the first line laser 127 and the second line laser 128 to the common PCB 129 in relation to the camera 123, the positions of the two line lasers 127, 128 are firmly maintained relatively to the camera 123 and a firm mechanical stability is attained.

[0044] Further, even though not shown in Figure 3, the common PCB 129 typically contains wirings connecting the camera 123 and the two line lasers 127, 128 to the controller 116.

[0045] In the embodiment shown in Figure 3, the camera 123 is further mounted to a sensor printed circuit board 130.

[0046] Figures 4-6 show the obstacle detecting arrangement 200 according to an embodiment in a top view, a front view and a bottom view, respectively.

[0047] In the views of Figures 4-6, it is illustrated that each of the first line laser 127 and the second line laser 128 are fixedly mounted to the common PCB 129 by means of a pair of fasteners 131, 132 and 133, 134, respectively, while the camera 123 is fixedly mounted to the common PCB 129 via another pair of fasteners 135, 136. Any suitable fastener may be used, such as a screw and nut. It may also be envisaged that soldering or spot welding is utilized for the fastening.

[0048] Thus, the obstacle detecting arrangement 200 according to embodiments advantageously provides for a rigid mechanical coupling between the camera 123 and the lasers 127, 128.

[0049] As shown in Figure 5, the first line laser 127 and the second line laser 128 are arranged to illuminate any obstacles to be detected in a line of sight of the camera 123.

[0050] Further, while the camera 123 is attached in an upper end to the common PCB 129 by means of the pair of fasteners 135, 136, the camera 123 may also in an embodiment be mounted to the sensor PCB 130. As shown in Figure 6, connectors in the form of a cable bundle 137 may be attached to the sensor PCB 130 for connecting the camera 123 to e.g. the controller 116 and for powering the camera 123, and in particular for transporting captured image data from the camera 123 to the controller 116.

[0051] In an embodiment, the common PCB 129 may be reinforced with a rigid support component such as a plastic beam mounted on a top or bottom side of the common PCB 129 and extending at least partly along a length of the common PCB 129 to avoid the common PCB 129 flexing in a vertical direction.

[0052] Figure 7 illustrates a structured light source in the form of the first line laser 127. As is understood, this is an example only and any appropriate structured light source may be utilized. The first line laser 127 comprises an upper chassis 127a and a lower chassis 127b assembled to house a laser diode 127b and a lens 127c.

Further shown is the pair of fasteners 131, 132 (in the form of screw and nuts) used to mount the first line laser 127 to the common PCB 129 and a further fastener 138 for assembling the upper and lower chassis 127a, 127b.

[0053] Figure 8 illustrates a light detecting sensor in the form of the camera 123. Again, this is an example only and any appropriate light detecting sensor may be utilized. The camera 123 is mounted to the common PCB 129 using the pair of fasteners 135, 136 (in the form of screw and nuts). The camera 123 may further be mounted to the sensor PCB 130 to which the connectors 137 are attached.

[0054] The aspects of the present disclosure have mainly been described above with reference to a few embodiments and examples thereof. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the disclosure, as defined by the appended patent claims.

[0055] Thus, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

CLAIMS i. Obstacle detecting arrangement (200) in a robotic cleaning device (100), the arrangement comprising: a light detecting sensor (123) configured to detect obstacles in an environment in which the robotic cleaning device (100) moves; at least a first structured light source (127) configured to illuminate the obstacles to be detected in a line of sight of the light detecting sensor (123); and a common printed circuit board (129) to which the light detecting sensor (123) and said first structured light source (127) are fixedly mounted.

2. The obstacle detecting arrangement (200) of claim 1, further comprising: at least a second structured light source (128) configured to illuminate the obstacles to be detected in the line of sight of the light detecting sensor (123), the second structured light source (128) being symmetrically arranged on an opposite side of the light detecting sensor (123) with respect to the first structured light source (127) and mounted fixedly to the common printed circuit board (129).

3. The obstacle detecting arrangement (200) of claims 1 or 2, further comprising: a sensor printed circuit board (130) to which the light detecting sensor (123) further is mounted.

4. The obstacle detecting arrangement (200) of claim 3, further comprising: connectors (137) being attached to the sensor printed circuit board (130) for transporting data to a controller (116) of the robotic cleaning device (100).

5. The obstacle detecting arrangement (200) of claims 3 or 4, wherein the sensor printed circuit board (130) is configured to be mounted with one end abutting the common printed circuit board (129).

6. The obstacle detecting arrangement (200) of any one of the preceding claims, the light detecting sensor (123), the first structured light source (127) and the second structured light source (128) being configured to be fixedly mounted to the common printed circuit board (129) by means of fasteners (131-136), soldering or welding.

7. The obstacle detecting arrangement (200) of any one of the preceding claims, the light detecting sensor (123) comprising a camera.

8. The obstacle detecting arrangement (200) of any one of the preceding claims, the first structured light source (127) and the second structured light source (128) each comprising a laser.

9. The obstacle detecting arrangement (200) of any one of the preceding claims, further comprising a support component mounted to the common printed circuit board (129).

10. A robotic cleaning device (100) comprising the obstacle detecting arrangement (200) of any one of the preceding claims.