Visual identification and positioning system of a robotic lawnmower

Abstract

A positioning system with visual identification comprises a first positioning element, a second positioning element, and a robotic lawnmower. The robotic lawnmower has a visual identification unit and a processing unit. The visual identification unit identifies a first identification feature of the first positioning element and a second identification feature of the second positioning element to generate a first and a second signal for the processing unit.The calculation unit calculates a first coordinate, a second coordinate, a first distance between the robotic lawnmower and the first coordinate, and a second distance between the robotic lawnmower and the second coordinate according to the first and second signals, defines first and second areas with the first and second coordinates as centers according to the first and second distances, and calculates a coordinate of an intersection point of the first and second areas as a current location coordinate of the robotic lawnmower.

Description

BACKGROUND OF THE INVENTION 1. Technical field

[0001] The present invention relates to robotic lawnmowers and, more particularly, to a visual identification positioning system of a robotic lawnmower. 2. State of the art

[0002] In order for a robotic lawnmower to move towards a target point, patent CN 1 13 207 412 A discloses a visual servo-guided robotic lawnmower and a target tracking method based thereon. The aforementioned patent comprises the following steps: enabling the positioning of a target point in a field of view of a rotating camera and detecting a first included angle between the heading of the robotic lawnmower (i.e., the current direction of travel of the robotic lawnmower) and the optical axis of the rotating camera (i.e., the center line of the beam at the center of the rotating camera) and a second included angle between a preset track of the target point in the field of view of the rotating camera and the optical axis, and adjusting the heading of the robotic lawnmower according to the first included angle and the second included angle to enable the robotic lawnmower to continuously track the target point and gradually reach the target point.However, the aforementioned prior art involves relatively laborious positioning and is expensive. DE 10 2019 219 758 A1 discloses a vibrating plate for soil compaction with automatic movement control, which has a detection device for detecting a predetermined boundary of the movement area. CN 1 11 045 423 A discloses a robotic mower that determines its position using UWB triangulation and at least three fixed stations. WO 2021 / 066 343 A1 discloses a robotic mower that triangulates its own position relative to an electronically stored map using at least three radio beacons of known position and optical sensors. CN 2 05 485 614 U discloses a cleaning robot for which a cleaning area can be specified using visual elements and which locates itself in the electronic map created by the robot. SUMMARY OF THE INVENTION

[0003] A main object of the present invention is to provide a visual identification positioning system for use with a robotic lawnmower that offers a relatively simple and fast positioning method and is lower in cost.

[0004] To achieve the above object, the visual identification positioning system of the present invention comprises a first positioning element, a second positioning element, and a robotic lawnmower. The first positioning element has a first identification feature. The second positioning element is spaced apart from the first positioning element and has a second identification feature. The robotic lawnmower includes a visual identification unit and a calculation unit. The visual identification unit identifies the first identification feature of the first positioning element and the second identification feature of the second positioning element to generate a first signal and a second signal for the calculation unit.The calculation unit calculates a first coordinate of the first positioning element, a second coordinate of the second positioning element, a first distance between the robotic lawnmower and the first coordinate, and a second distance between the robotic lawnmower and the second coordinate according to the first and second signals, and defines first and second areas with the first and second coordinates as centers according to the first and second distances, and calculates a coordinate of at least one intersection point of the first and second areas as a current location coordinate of the robotic lawnmower.

[0005] It can be seen from the above that the visual identification positioning system of the present invention can detect the current location coordinate of the robotic lawnmower without using satellite positioning, and further, the first and second positioning elements are easy to manufacture in large quantities, so that the visual identification positioning system of the present invention provides a relatively simple and fast positioning method and has a lower cost compared to the prior art.

[0006] In a preferred embodiment of the present invention, the calculation unit defines a first boundary between the first and second coordinates according to the first and second signals and calculates a first distance between the robotic lawnmower and the first boundary. If the first distance is zero, the robotic lawnmower cannot cross the first boundary and moves away from the first boundary. In this way, the movement range of the robotic lawnmower can be restricted by the first boundary.

[0007] In a preferred embodiment of the present invention, the first and second regions are circles defined with the first and second coordinates as centers and the first and second distances as radii.

[0008] In a further preferred embodiment of the present invention, the visual identification positioning system further comprises a third positioning element spaced from the first and second positioning elements and having a third identification feature. The visual identification unit identifies the third identification feature of the third positioning element to generate a third signal to the calculation unit. The calculation unit calculates a third coordinate of the third positioning element, a third distance between the robotic lawnmower and the third coordinate, and defines the first area, the second area, and a third area with the first, second, and third coordinates as centers according to the first, second, and third distances, and calculates a coordinate of an intersection point of the first, second, and third areas as the current location coordinate of the robotic lawnmower.In this way, the current location coordinate of the robotic lawnmower can be more accurate using the first, second, and third ranges defined by the first, second, and third positioning elements. In a further preferred embodiment of the present invention, the calculation unit defines the first boundary between the first and second coordinates, a second boundary between the second and third coordinates, and a third boundary between the first and third coordinates according to the first, second, and third signals, and calculates the first distance between the robotic lawnmower and the first boundary, a second distance between the robotic lawnmower and the second boundary, and a third distance between the robotic lawnmower and the third boundary.If one of the first, second, and third distances is zero, the robotic lawnmower cannot cross one of the first, second, and third boundaries and moves away from one of the first, second, and third boundaries. In this way, the movement range of the robotic lawnmower can be more precisely limited by the first, second, and third boundaries. To achieve the above-mentioned object, the present invention provides a further visual identification positioning system comprising a first positioning element, a second positioning element, at least one lens, a transmission element, and a robotic lawnmower. The first positioning element has a first identification feature. The second positioning element is spaced from the first positioning element and has a second identification feature.The lens identifies the first identification feature of the first positioning element and the second identification feature of the second positioning element. The transmission element receives and transmits the first and second identification features identified by the lens. The robotic lawnmower includes a visual identification unit and a calculation unit. The visual identification unit receives the first and second identification features transmitted by the transmission element and generates a first signal and a second signal for the calculation unit.The calculation unit calculates a first coordinate of the first positioning element, a second coordinate of the second positioning element, a first distance between the robotic lawnmower and the first coordinate, and a second distance between the robotic lawnmower and the first coordinate according to the first and second signals, and defines first and second areas with the first and second coordinates as centers according to the first and second distances, and calculates a coordinate of at least one intersection point of the first and second areas as a current location coordinate of the robotic lawnmower.It can be seen from the above that the visual identification positioning system of the present invention can detect the current location coordinates of the robotic lawnmower without using satellite positioning, and furthermore, the first and second positioning elements are easy to manufacture in large quantities, so that the visual identification positioning system of the present invention offers a relatively simple and fast positioning possibility and has a lower cost compared to the prior art.

[0009] In a further preferred embodiment of the present invention, the lens identifies a mowing area and a boundary of the mowing area. The transmission element transmits information corresponding to the mowing area and the boundary to the calculation unit. When the robotic lawnmower moves to the boundary of the mowing area, it moves along the boundary of the mowing area, and a new boundary of the mowing area is defined by a current location coordinate of the robotic lawnmower moving along the boundary. In this way, the lens does not repeatedly identify the mowing area and the boundary of the mowing area, and it is also ensured that the robotic lawnmower moves at most to the boundary of the mowing area without crossing the boundary.

[0010] Further advantages and features of the present invention will be fully understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals designate like structural components. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a system block diagram of a visual identification positioning system of a first embodiment of the present invention; Fig. 2 is a perspective view of the visual identification positioning system of the first embodiment of the present invention, showing that the visual identification unit identifies the first positioning element and the second positioning element; Fig. 3 is a plan view of the visual identification positioning system of the first embodiment of the present invention, showing that the current location coordinate of the robotic lawnmower is defined by the coordinate of the intersection point of the first and second areas; Fig. 4 is a system block diagram of the visual identification positioning system of a second embodiment of the present invention; Fig. 5 is a perspective view of the visual identification positioning system of the second embodiment of the present invention, showing that the visual identification unit identifies the first, second, and third positioning elements; Fig. 6 is a plan view of the visual identification positioning system of the second embodiment of the present invention, showing that the current location coordinate of the robotic lawnmower is defined by the coordinate of the intersection point of the first, second, and third areas; Fig. 7 is a system block diagram of the visual identification positioning system of a third embodiment of the present invention; Fig. 8 is a plan view of the visual identification positioning system of the third embodiment of the present invention, showing that the current location coordinate of the robotic lawnmower is defined by the coordinate of the intersection point of the first and second areas; and Fig. 9 is similar to Fig. 8 and shows that the robotic lawnmower is located at the edge of the mowing area and the current location coordinate of the robotic lawnmower is defined by the coordinate of the intersection point of the first and second areas. DETAILED DESCRIPTION OF THE INVENTION

[0011] With reference to Fig. 1, a visual identification positioning system 1 of a first embodiment of the present invention comprises a first positioning element 10, a second positioning element 20 and a robotic lawnmower 30.

[0012] The first positioning element 10 has a first identification feature 11. The second positioning element 20 has a second identification feature 21, and the second positioning element 20 and the first positioning element 10 are spaced apart from each other (as in Fig. 2). The first and second positioning elements 10, 20 may be, but are not limited to, landscaping elements. The first and second identification features 11, 21 may be, but are not limited to, patterns, characters, or a combination of patterns and characters. In the specific application, the first and second identification features 11, 21 may be affixed or printed on the first and second positioning elements 10, 20, respectively.

[0013] The robotic lawnmower 30 includes a visual identification unit 31 and a calculation unit 36. The visual identification unit 31 is used to identify a target and includes one or more lenses 32, a drive tripod head 33 that drives the lens 32 to rotate, and a database 34 in which a plurality of identification features 35 are stored. The visual identification unit 31 can, for example, be equipped with one lens 32 that can be rotated 360 degrees, or with two lenses 32 that can be individually rotated 180 degrees, or with three lenses 32 that can be individually rotated 120 degrees. Thus, the visual identification unit 31 has a field of view of 360 degrees. If the target is outside the field of view, the drive tripod head 33 drives the lens 32 to rotate until the target appears in the field of view, so that the target is identified by the visual identification unit 31.

[0014] In this embodiment, the visual identification unit 31 comprises two lenses 32. One of the lenses 32 identifies the first identification feature 11 of the first positioning element 10 and the other of the lenses 32 identifies the second identification feature 21 of the second positioning element 20. If the first and second identification features 11, 21 match the identification features 35 stored in the database 34, the visual identification unit 31 generates a first signal corresponding to the first identification feature 11 and a second signal corresponding to the second identification feature 21 and transmits the first and second signals to the calculation unit 36 ​​to facilitate subsequent operations of the calculation unit 36.

[0015] As in Fig. 2, the calculation unit 36 ​​calculates a first coordinate of the first positioning element 10, a second coordinate of the second positioning element 20, a first distance D1 between the robotic lawnmower 30 and the first coordinate, and a second distance D2 between the robotic lawnmower 30 and the second coordinate according to the first and second signals, wherein the first coordinate is a relative coordinate between the robotic lawnmower 30 and the first positioning element 10, and the second coordinate is a relative coordinate between the robotic lawnmower 30 and the second positioning element 20, and the first distance D1 is a relative distance between the robotic lawnmower 30 and the first coordinate, and the second distance D2 is a relative distance between the robotic lawnmower 30 and the second coordinate.Furthermore, the calculation unit 36 ​​defines a first boundary L1 between the first and second coordinates and calculates a first distance D3 between the robotic lawnmower 30 and the first boundary L1. If the first distance D3 is zero, the robotic lawnmower 30 cannot cross the first boundary L1 and moves away from the first boundary L1. In this way, the movement range of the robotic lawnmower 30 can be restricted by the first boundary L1. As shown in FIG. Fig. As shown in Figure 3, the calculation unit 36 ​​defines a first area C1 defined by a circle with the first coordinate as the center point and the first distance D1 as the radius, and defines a second area C2 defined with the second coordinate as the center point and the second distance D2 as the radius. Then, the calculation unit 36 ​​calculates a coordinate of the intersection point of the first and second areas C1, C2 (i.e., the intersection point of two circles) as the current location coordinate of the robotic lawnmower 30.

[0016] As in Fig. As shown in Figure 4, the main structure of the visual identification positioning system 2 provided by a second embodiment of the present invention is approximately the same as the first embodiment, but one of the differences therebetween is that the visual identification positioning system 2 further includes a third positioning element 40 spaced apart from the first and second positioning elements 10, 20. The third positioning element 40 has a third identification feature 41. The third positioning element 40 may be, but is not limited to, a landscaping feature. The third identification features 41 may be, but are not limited to, patterns, characters, or a combination of patterns and characters.In actual application, the visual identification unit 31 uses two lenses 32 to identify the first identification feature 11 of the first positioning element 10, the second identification feature 21 of the second positioning element 20, and the third identification feature 41 of the third positioning element 40. If the first, second, and third identification features 11, 21, and 41 correspond to the identification features 35 stored in the database 34, the visual identification unit 31 generates the first signal corresponding to the first identification feature 11, the second signal corresponding to the second identification feature 21, and a third signal corresponding to the third identification feature 41, and transmits the first, second, and third signals to the calculation unit 36.

[0017] As in Fig. 5, the calculation unit 36 ​​calculates the first coordinate of the first positioning element 10, the second coordinate of the second positioning element 20, a third coordinate of the third positioning element 40, the first distance D1 between the robotic lawnmower 30 and the first coordinate, the second distance D2 between the robotic lawnmower 30 and the second coordinate, and a third distance D4 between the robotic lawnmower 30 and the third coordinate.Furthermore, the calculation unit 36 ​​defines the first boundary L1 between the first and second coordinates, a second boundary L2 between the second and third coordinates, and a third boundary L3 between the first and third coordinates according to the first, second, and third signals, and calculates the first distance D3 between the robotic lawnmower 30 and the first boundary L1, a second distance D5 between the robotic lawnmower 30 and the second boundary L2, and a third distance D6 between the robotic lawnmower 30 and the third boundary L3. If one of the first, second, and third distances D3, D5, D6 is zero, the robotic lawnmower 30 cannot cross one of the first, second, and third boundaries L1, L2, L3 and moves away from one of the first, second, and third boundaries L1, L2, L3. For example, if the third distance D6 is zero, the robotic lawnmower 30 cannot cross the third boundary L3 and moves away from the third boundary L3.In this way, the range of movement of the robotic lawnmower 30 can be more precisely restricted by the first, second and third boundaries L1, L2, L3.

[0018] As in Fig. As shown in Figure 6, the calculation unit 36 ​​defines a first area C1 defined by a circle with the first coordinate as the center point and the first distance D1 as the radius, a second area C2 defined by the second coordinate as the center point and the second distance D2 as the radius, and a third area C3 defined by a circle with the third coordinate as the center point and the third distance D4 as the radius. Then, the calculation unit 36 ​​calculates a coordinate of the intersection point of the first, second, and third areas C1, C2, C3 (i.e., the intersection point of the three circles) as a current location coordinate of the robotic lawnmower 30. In this way, the current location coordinate of the robotic lawnmower 30 can be more accurately determined using the first, second, and third areas C1, C2, C3 defined by the first, second, and third positioning elements 10, 20, 40.However, the number of third positioning elements 40 is not limited to those disclosed in this embodiment. The visual identification positioning system 2 of the present invention may provide multiple third positioning elements 40 to make the current location coordinate of the robotic lawnmower 30 more accurate and significantly limit the movement range of the robotic lawnmower 30.

[0019] As in Fig. As shown in Figure 7, the main structure of the visual identification positioning system 3 provided by a third embodiment of the present invention is approximately the same as that of the first embodiment, but one of the differences is that the lenses 32 and the drive tripod head 33 are arranged outside the robotic lawnmower 30 (e.g., a fence or a roof near the mowing field), and a transmission element 37 is added. The lenses 32 serve to recognize the first and second identification features 11, 21. The transmission element 37 serves to receive the first and second identification features 11, 21 identified by the lenses 32 and transmits the first and second identification features 11, 21 to the visual identification unit 31 of the robotic lawnmower 30.If the first and second identification features 11, 21 correspond to the identification features 35 stored in the database 34 of the visual identification unit 31, the visual identification unit 31 generates the first signal corresponding to the first identification features 11 and the second signal corresponding to the second identification features 21 and transmits the first and second signals to the calculation unit 36. The calculation unit 36 ​​calculates the first coordinate of the first positioning element 10, the second coordinate of the second positioning element 20, the first distance D1 between the robotic lawnmower 30 and the first coordinate and the second distance D2 between the robotic lawnmower 30 and the second coordinate according to the first and second signals, as shown in FIG. Fig. 8. Then the calculation unit 36 ​​defines, as in Fig. 8, the first area C1 is defined by a circle with the first coordinate as the center and the first distance D1 as the radius, and defines the second area C2 is defined with the second coordinate as the center and the second distance D2 as the radius. Then, the calculation unit 36 ​​calculates a coordinate of the intersection point of the first and second areas C1, C2 (i.e., the intersection point of two circles) as the current location coordinate of the robotic lawnmower 30. However, in this embodiment, the transmission element 37 may directly calculate the current location coordinate of the robotic lawnmower 30 and transmit the current location coordinate to the robotic lawnmower 30 for positioning; that is, the robotic lawnmower 30 may replace the transmission element 37 with the calculation unit 36.

[0020] Furthermore, the lenses 32 can identify a mowing area C4 of the robotic lawnmower 30 and a boundary L4 of the mowing area C4, and the transmission element 37 transmits information including the mowing area C4 and the boundary L4 to the calculation unit 36. As in Fig. 8, the calculation unit 36 ​​uses the first and second positioning elements 10, 20 to calculate the current location coordinate for the robotic lawnmower 30, and as shown in Fig.As shown in Figure 9, the calculation unit 36 ​​calculates the current location coordinate for the robotic lawnmower 30 when the robotic lawnmower 30 moves to the boundary L4 of the mowing area C4 and the robotic lawnmower 30 moves along the boundary L4 of the mowing area C4. As such, the robotic lawnmower 30 records all current location coordinates of the robotic lawnmower 30 as it moves along the boundary L4, so that a new boundary L5 is defined with the aforementioned information using the aforementioned current location coordinates. Theoretically, the new boundary L5 coincides with the boundary L4 identified by the lenses 32. In this way, it is not necessary for the lenses 32 to repeatedly identify the mowing area C4 and the boundary L4. As long as the robotic lawnmower 30 detects the current location coordinate, the robotic lawnmower 30 can judge by itself whether it is near or even at the new boundary L5 (i.e., the boundary L4).Therefore, the robotic lawnmower 30 can be sure that it will move at most to the boundary L4 of the mowing area C4 without going beyond the boundary L4.

[0021] As mentioned above, the visual identification positioning system 1, 2, 3 of the present invention can detect the current location coordinate of the robotic lawnmower 30 without using satellite positioning, and furthermore, the first, second and third positioning elements 10, 20, 40 are easy to manufacture in large quantities, so that the visual identification positioning system 1, 2, 3 of the present invention provides a relatively simple and fast positioning method and has a lower cost compared to the prior art.

Claims

[1] Visual identification positioning system (1)(2), comprising: a first positioning element (10) with a first identification feature (11); a second positioning element (20) spaced from the first positioning element (10) and having a second identification feature (21); and a robotic lawnmower (30) comprising a visual identification unit (31) and a calculation unit (36), wherein the visual identification unit (31) identifies the first identification feature (11) of the first positioning element (10) and the second identification feature (21) of the second positioning element (20) to generate a first signal and a second signal and transmits the first and second signals to the calculation unit (36), wherein the calculation unit (36) calculates a first coordinate of the first positioning element (10), a second coordinate of the second positioning element (20), a first distance (D1) between the robotic lawnmower (30) and the first coordinate, and a second distance (D2) between the robotic lawnmower (30) and the second coordinate according to the first and second signals, and defines first and second areas (C1)(C2) with the first and second coordinates as centers according to the first and second distances (D1)(D2),and a coordinate of at least one intersection point of the first and second areas (C1)(C2) is calculated as a current location coordinate of the robotic lawnmower (30). [2] Visual identification positioning system (1) according to claim 1, wherein the calculation unit (36) defines a first boundary (L1) between the first and second coordinates according to the first and second signals and calculates a first distance (D3) between the robotic lawnmower (30) and the first boundary (L1); wherein, if the first distance (D3) is zero, the robotic lawnmower (30) cannot cross the first boundary (L1) and moves away from the first boundary (L1). [3] Visual identification positioning system (1) according to claim 2, wherein the first and second areas (C1) (C2) are defined with the first and second coordinates as centers and the first and second distances (D1) (D2) as radii, respectively. [4] A visual identification positioning system (1) according to claim 3, further comprising a third positioning element (40) spaced from the first and second positioning elements (10) (20) and having a third identification feature (41); wherein the visual identification unit (31) identifies the third identification feature (41) of the third positioning element (40) to generate a third signal and transmit the third signal to the calculation unit (36);the calculation unit (36) calculates a third coordinate of the third positioning element (40), a third distance (D4) between the robotic lawnmower (30) and the third coordinate, and defines the first area (C1), the second area (C2), and a third area (C3) with the first, second, and third coordinates as centers according to the first, second, and third distances (D1)(D2)(D4), and calculates a coordinate of an intersection point of the first, second, and third areas (C1)(C2)(C3) as the current location coordinate of the robotic lawnmower (30); [5] Visual identification positioning system (1) according to claim 4, wherein the calculation unit (36) defines the first boundary (L1) between the first and second coordinates, a second boundary (L2) between the second and third coordinates and a third boundary (L3) between the first and third coordinates according to the first, second and third signals and calculates the first distance (D3) between the robotic lawnmower (30) and the first boundary (L1), a second distance (D5) between the robotic lawnmower (30) and the second boundary (L2) and a third distance (D6) between the robotic lawnmower (30) and the third boundary (L3); wherein, if one of the first, second and third spaced distances (D1)(D5)(D6) is zero, the robotic lawnmower (30) cannot cross one of the first, second and third boundaries (L1)(L2)(L3) and moves away from one of the first, second and third boundaries (L1)(L2)(L3). [6] Visual identification positioning system (3), comprising: a first positioning element (10) with a first identification feature (11); a second positioning element (20) spaced from the first positioning element (10) and having a second identification feature (21); at least one lens (32) that identifies the first identification feature (11) of the first positioning element (10) and the second identification feature (21) of the second positioning element (20); a transmission element (37) which receives and transmits the first and second identification features (11) (21) identified by the lens (32); and a robotic lawnmower (30) comprising a visual identification unit (31) and a calculation unit (36), wherein the visual identification unit (31) receives the first and second identification features (11)(21) transmitted by the transmission element (37) and generates a first signal and a second signal and transmits the first and second signals to the calculation unit (36), wherein the calculation unit (36) calculates a first coordinate of the first positioning element (10), a second coordinate of the second positioning element (20), a first distance (D1) between the robotic lawnmower (30) and the first coordinate, and a second distance (D2) between the robotic lawnmower (30) and the second coordinate according to the first and second signals, and defines first and second areas (C1)(C2) with the first and second coordinates as centers according to the first and second distances (D1)(D2),and a coordinate of at least one intersection point of the first and second areas (C1)(C2) is calculated as a current location coordinate of the robotic lawnmower (30). [7] Visual identification positioning system (3) according to claim 6, wherein the first and second areas (C1)(C2) are defined with the first and second coordinates as centers and the first and second distances (D1)(D2) as radii, respectively. [8] Visual identification positioning system (3) according to claim 7, wherein the lens (32) identifies a mowing area (C4) and a boundary (L4) of the mowing area (C4); the transmission element (37) transmits information corresponding to the mowing area (C4) and the boundary (L4) to the calculation unit (36); wherein, when the robotic lawnmower (30) moves to the boundary (L4) of the mowing area (C4), the robotic lawnmower (30) moves along the boundary (L4) of the mowing area (C4), and a new boundary (L5) of the mowing area (C4) is defined by a current location coordinate of the robotic lawnmower (30) moving along the boundary (L4).

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