U.S. patent application number 17/313207 was filed with the patent office on 2021-11-11 for outdoor robotic work tool comprising an environmental detection system.
The applicant listed for this patent is Husqvarna AB. Invention is credited to Ulf Arlig, Jimmy Petersson.
Application Number | 20210349464 17/313207 |
Document ID | / |
Family ID | 1000005926026 |
Filed Date | 2021-11-11 |
United States Patent
Application |
20210349464 |
Kind Code |
A1 |
Arlig; Ulf ; et al. |
November 11, 2021 |
Outdoor Robotic Work Tool Comprising an Environmental Detection
System
Abstract
The present disclosure relates to an outdoor robotic work tool
(1) adapted for a forward traveling direction (D) and comprising an
environmental detection system (19) that comprises a set of outer
detector transceivers (2a, 2b) and a set of inner detector
transceivers (3a, 3b), where the inner detector transceivers (3a,
3b) are positioned between the outer detector transceivers (2a,
2b). Each detector transceiver (2a, 2b; 3a, 3b) is adapted to
transmit signals (4a, 4b; 5a, 5b) and to receive reflected signals
(6a, 6b, 9) that have been reflected by an object (10, 11). The
outer detector transceivers (2a, 2b) are associated with outer
coverage main directions (7a, 7b) that are directed at
corresponding outer angles (.alpha..sub.a, .alpha..sub.b) to the
forward traveling direction (D), and the inner detector
transceivers (3a, 3b) are associated with inner coverage main
directions (8a, 8b) that are directed at corresponding inner angles
(.beta..sub.a, .beta..sub.b) to the forward traveling direction
(D). The inner angles (.beta..sub.a, .beta..sub.b) have magnitudes
that exceed the magnitudes of the outer angles (.alpha..sub.a,
.alpha..sub.b), and the inner coverage main directions (8a, 8b)
intersect in front of the outdoor robotic work tool (1) in the
forward traveling direction (D).
Inventors: |
Arlig; Ulf; (Bankeryd,
SE) ; Petersson; Jimmy; (Jonkoping, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Husqvarna AB |
Huskvarna |
|
SE |
|
|
Family ID: |
1000005926026 |
Appl. No.: |
17/313207 |
Filed: |
May 6, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G05D 1/0257 20130101;
G05D 1/0214 20130101 |
International
Class: |
G05D 1/02 20060101
G05D001/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2020 |
SE |
2050539-2 |
Claims
1. An outdoor robotic work tool adapted for a forward traveling
direction and comprising an environmental detection system that
comprises a set of outer detector transceivers and a set of inner
detector transceivers, wherein the inner detector transceivers are
positioned between the outer detector transceivers, wherein each of
the inner and outer detector transceivers is adapted to transmit
signals and to receive reflected signals that have been reflected
by an object, wherein the outer detector transceivers are
associated with outer coverage main directions that are directed at
corresponding outer angles to the forward traveling direction, and
the inner detector transceivers are associated with inner coverage
main directions that are directed at corresponding inner angles to
the forward traveling direction, wherein the inner angles have
magnitudes that exceed the magnitudes of the outer angles, and
wherein the inner coverage main directions intersect in front of
the outdoor robotic work tool in the forward traveling
direction.
2. The outdoor robotic work tool according to claim 1, wherein each
of the inner and outer coverage main directions is associated with
a corresponding transceiver coverage, wherein a combined
rectangular coverage having a certain width is formed in front of
the outdoor robotic work tool in the forward traveling direction,
wherein the combined rectangular coverage comprises at least two
separate transceiver coverages.
3. The outdoor robotic work tool according to claim 1, wherein the
outer angles are equal to each other in magnitude and the inner
angles are equal to each other in magnitude.
4. The outdoor robotic work tool according to claim 1, wherein the
outer coverage main directions do not intersect in front of the
outdoor robotic work tool in the forward traveling direction.
5. The outdoor robotic work tool according to claim 1, wherein the
outer coverage main directions are mutually parallel.
6. The outdoor robotic work tool according to claim 1, wherein the
detector transceivers are adapted to transmit signals at least
partly at the same time.
7. The outdoor robotic work tool according to claim 1, wherein the
detector transceivers are any one of radar transceivers, ultrasonic
transceivers or Lidar transceivers.
8. The outdoor robotic work tool according to claim 1, wherein the
robotic work tool is a robotic lawn mower.
9. The outdoor robotic work tool according to claim 1, wherein the
robotic work tool comprises a first outer detector transceiver, a
second outer detector transceiver, a first inner detector
transceiver and a second inner detector transceiver.
10. The outdoor robotic work tool according to claim 1, wherein the
robotic work tool comprises a propulsion motor arrangement, a power
source adapted to provide power to the propulsion motor
arrangement, a plurality of wheels wherein at least two wheels are
adapted to be propelled by the propulsion motor arrangement, and a
control unit that is adapted to control the detector transceivers
and to control a speed and direction of the robotic work tool in
dependence of information acquired by means of the detector
transceivers when the robotic work tool is moving.
11. (canceled)
12. An outdoor robotic work tool adapted for a forward traveling
direction and comprising an environmental detection system that
comprises at least two detector transceivers that are adapted to
transmit signals and to receive reflected signals that have been
reflected by an object, wherein the detector tranceivers are
adapted to transmit signals at least partly at the same time,
wherein the robotic work tool comprises a set of outer detector
transceivers, a set of inner detector transceiver, wherein the
inner detector transceivers are positioned between the outer
detector transceivers, wherein the outer detector transceivers are
associated with outer coverage main directions that are directed at
corresponding outer angles to the forward traveling direction, and
the inner detector transceivers are associated with inner coverage
main directions that are directed at corresponding inner angles to
the forward traveling direction, wherein the inner angles have
magnitudes that exceed the magnitudes of the outer angles, and
wherein the inner coverage main directions intersect in front of
the outdoor robotic work tool in the forward traveling
direction.
13-31. (canceled)
Description
TECHNICAL FIELD
[0001] The present disclosure relates to outdoor robotic work tool
comprising an environmental detection system with a set of outer
detector transceivers and a set of inner detector transceivers. The
outdoor robotic work tool can for example be constituted by a
robotic lawn mower.
BACKGROUND
[0002] Automated or robotic power tools such as robotic lawn mowers
are becoming increasingly more popular. In a typical deployment a
work area, such as a garden, the work area is enclosed by a
boundary wire with the purpose of keeping the robotic lawn mower
inside the work area. An electric control signal may be transmitted
through the boundary wire thereby generating an (electro-) magnetic
field emanating from the boundary wire. The robotic working tool is
typically arranged with one or more sensors adapted to sense the
control signal.
[0003] The robotic lawn mower can then cut grass on a user's lawn
automatically and can be charged automatically without intervention
of the user, and no longer needs to be manually managed after being
set once. The robotic lawn mower needs to have a function of
recognizing an obstacle to avoid colliding with the obstacle before
encountering the obstacle, and to have a function of recognizing
that a collision has occurred.
[0004] In the latter case, a collision sensor can be disposed on
the body of the robotic lawn mower, and when the robotic lawn mower
collides with an obstacle, the body moves in such a way that the
collision sensor generates a collision signal. In the former case,
different kinds of environment detection sensors are use such as
ultrasonic sensors as disclosed in EP3508048 and radar sensors as
disclosed in SE540794.
[0005] There is, however, a need to improve the coverage, reliably
and efficiency of such environment detection sensors such that all
obstacles are detected in time such that a collision can be avoided
by stopping the robotic lawn mower and/or turning the robotic lawn
mower away from the obstacle.
SUMMARY
[0006] The object of the present disclosure is to provide a robotic
work tool with environment detection system that has an improved
coverage, reliably and efficiency compared to prior art.
[0007] This object is achieved by means of an outdoor robotic work
tool adapted for a forward traveling direction and comprising an
environmental detection system that comprises a set of outer
detector transceivers and a set of inner detector transceivers,
where the inner detector transceivers are positioned between the
outer detector transceivers. Each detector transceiver is adapted
to transmit signals and to receive reflected signals that have been
reflected by an object. The outer detector transceivers are
associated with outer coverage main directions that are directed at
corresponding outer angles to the forward traveling direction, and
the inner detector transceivers are associated with inner coverage
main directions that are directed at corresponding inner angles to
the forward traveling direction. The inner angles have magnitudes
that exceed the magnitudes of the outer angles, and the inner
coverage main directions intersect in front of the outdoor robotic
work tool in the forward traveling direction.
[0008] This means that a robotic work tool with an increased sensor
coverage is provided, increasing the robotic work tool's ability to
avoid collisions with other objects.
[0009] According to some aspects, each coverage main direction is
associated with a corresponding transceiver coverage, where a
combined rectangular coverage having a certain width is formed in
front of the outdoor robotic work tool in the forward traveling
direction, where the combined coverage comprises at least two
separate transceiver coverages.
[0010] Forming such a combined area increases the reliability of
the detections.
[0011] According to some aspects, the outer angles are of the same
magnitude and the inner angles are of the same magnitude.
[0012] According to some aspects, the outer coverage main
directions do not intersect in front of the outdoor robotic work
tool in the forward traveling direction.
[0013] In this way an increased coverage is enabled.
[0014] According to some aspects, the outer coverage main
directions are mutually parallel.
[0015] In this way, a desirable combined area is formed.
[0016] According to some aspects, the detector transceivers are
adapted to transmit signals at least partly at the same time.
[0017] In this way, objects in front of the robotic work tool are
detected in a quicker and more efficient manner.
[0018] According to some aspects, the detector transceivers are any
one of radar transceivers, ultrasonic transceivers or Lidar
transceivers.
[0019] This means that the present disclosure is applicable for
many types of detector transceivers.
[0020] According to some aspects, the robotic work tool is a
robotic lawn mower.
[0021] According to some aspects, the robotic work tool comprises a
first outer detector transceiver, a second outer detector
transceiver, a first inner detector transceiver and a second inner
detector transceiver.
[0022] According to some aspects, the robotic work tool comprises a
propulsion motor arrangement, a power source adapted to provide
power to the propulsion motor arrangement and a plurality of
wheels, where at least two wheels are adapted to be propelled by
the propulsion motor arrangement. The robotic work tool further
comprises a control unit that is adapted to control the detector
transceivers and to control the speed and direction of the robotic
work tool in dependence of information acquired by means of the of
the detector transceivers when the robotic work tool is moving.
[0023] In this manner, a safe and reliable control of the robotic
work tool is provided.
[0024] According to some aspects, the detector transceivers are
adapted to transmit signals at the same time at all detector
transceivers or at the same time at two or more detector
transceivers, in the same or in different constellations at
different times. Alternatively, or in combination, the detector
transceivers are adapted to transmit signals at only one detector
transceiver at a time at certain times.
[0025] This means that the simultaneous transmission can be adapted
either for different need that arise in dependence of detection
results and/or in dependence of a certain predetermined
scheduling.
[0026] According to some aspects, each detector transceiver is
adapted to transmit a signal comprising a specific signal
identification, such that a received signal can be identified with
respect to its transmitting detector transceivers. According to
some aspects, the signal identification is accomplished by means of
utilizing different waveforms or embedded identifications
codes.
[0027] In this way, specific details such as for example azimuth
heading and/or distance can be provided for the detected
objects.
[0028] The present disclosure also relates to methods that are
associated with above advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The present disclosure will now be described more in detail
with reference to the appended drawings, where:
[0030] FIG. 1 shows a first schematic top view of a lawn mower;
[0031] FIG. 2 shows a second schematic top view of a lawn
mower;
[0032] FIG. 3 shows a third schematic top view of a lawn mower;
[0033] FIG. 4 shows a schematic front view of a lawn mower;
[0034] FIG. 5 shows a schematic bottom view of a lawn mower;
[0035] FIG. 6 schematically illustrates processing circuitry;
[0036] FIG. 7 shows a computer program product; and
[0037] FIG. 8 shows a flowchart for methods according to the
present disclosure.
DETAILED DESCRIPTION
[0038] Aspects of the present disclosure will now be described more
fully hereinafter with reference to the accompanying drawings. The
different devices, systems, computer programs and methods disclosed
herein can, however, be realized in many different forms and should
not be construed as being limited to the aspects set forth herein.
Like numbers in the drawings refer to like elements throughout.
[0039] The terminology used herein is for describing aspects of the
disclosure only and is not intended to limit the invention. As used
herein, the singular forms "a", "an" and "the" are intended to
include the plural forms as well, unless the context clearly
indicates otherwise.
[0040] It should be noted that even though the description given
herein will be focused on robotic lawn mowers, the teachings herein
may also be applied to any type of outdoor robotic work tool, such
as for example robotic ball collectors, robotic mine sweepers and
robotic farming equipment.
[0041] FIG. 1 shows a top view of a robotic working tool 1, FIG. 4
shows a front view of the robotic working tool 1 and FIG. 5 shows a
bottom view of the robotic working tool 1, here exemplified by a
robotic lawn mower 1. The robotic lawn mower 1 comprises a body
20a, 20b, a propulsion motor arrangement 15, a power source 16 such
as a rechargeable battery adapted to provide power to the
propulsion motor arrangement 15, and a plurality of wheels 17a,
17b; 21a, 21b, where two or more of the wheels, according to some
aspects two rear wheels 21a, 21b, are adapted to be propelled by
the propulsion motor arrangement 15, enabling the robotic working
tool 1 to move with respect to a forward traveling direction D. It
is of course possible that all four wheels 17a, 17b; 21a, 21b are
adapted to be propelled by the propulsion motor arrangement 15.
[0042] The robotic lawn mower 1 also comprises a grass cutting
device 23, in this example a plurality of cutting blade
arrangements driven by a cutter motor arrangement 22 that also is
powered by the power source 16 or, alternatively, by a separate
power source. The grass cutting device is an example of a general
work tool for a robotic work tool.
[0043] According to some aspects, the propulsion motor arrangement
15 comprises one separate propulsion motor for each wheel 17a, 17b;
21a, 21b to be driven, and according to some further aspects, the
cutter motor arrangement 22 comprises one separate cutter motor for
each cutting blade arrangement.
[0044] 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.
[0045] The robotic lawn mower 1 further comprises a control unit
18. The robotic lawn mower 1 may be a multi-chassis type or a
mono-chassis type. A multi-chassis type comprises more than one
body parts that are movable with respect to one another. A
mono-chassis type comprises only one main body part. In this
example there is a front body part 20a and a rear body part
20b.
[0046] The robotic lawn mower 1 typically comprises charging skids
28 for contacting contact plates in a charging station when docking
into the charging station for receiving a charging current through,
and possibly also for transferring information by means of
electrical communication between the charging station and the
robotic lawn mower 1. Other means of establishing a charging
contact are possible and are incorporated herein.
[0047] In a previously well-known manner, the robotic lawn mower 1
is adapted to navigate with reference to a boundary wire emitting a
magnetic field caused by a control signal transmitted through the
boundary wire. The robotic lawn mower is further configured to
detect the magnetic field and for detecting the boundary wire, for
example by means of one or more magnetic field sensors. It is also
conceivable that the robotic lawn mower 1 is adapted to navigate
without a boundary wire, other navigation systems are conceivable,
for example navigation systems based on GPS and/or one or more
wireless communication systems.
[0048] The robotic lawn mower 1 further comprises an environmental
detection system 19 that comprises a set of outer detector
transceivers 2a, 2b and a set of inner detector transceivers 3a,
3b. The inner detector transceivers 3a, 3b are positioned between
the outer detector transceivers 2a, 2b along an extension E that is
perpendicular to the forward traveling direction D. According to
some aspects, all detector transceivers 2a, 2b; 3a, 3b are
positioned along the extension E, and one or more detector
transceiver can according to some further aspects be mutually
displaced along the forward traveling direction D. In this example
the inner detector transceivers 3a, 3b are displaced along the
forward traveling direction D with respect to the outer detector
transceivers 2a, 2b as will be discussed more later.
[0049] It is also conceivable that the detector transceivers 2a,
2b; 3a, 3b are positioned along an extension that is inclined with
respect to the forward traveling direction D, or that the detector
transceivers 2a, 2b; 3a, 3b are positioned in an irregular manner.
According to some aspects, the inner detector transceivers 3a, 3b
are positioned between the outer detector transceivers 2a, 2b along
an extension and one or more detector transceiver can according to
some further aspects be mutually displaced in a direction
perpendicular to that extension. That extension can be any suitable
extension, not having to be the extension E that is perpendicular
to the forward traveling direction D.
[0050] With reference also to FIG. 3, Each detector transceiver 2a,
2b; 3a, 3b is adapted to transmit signals 4a, 4b; 5a, 5b and to
receive reflected signals 6a, 6b, 9 that have been reflected by an
object 10, 11. According to some aspects, the detector transceivers
2a, 2b; 3a, 3b are ultrasonic detector transceivers, being adapted
to transmit and receive ultrasonic signals. This should not be
regarded as limiting; the detector transceivers 2a, 2b; 3a, 3b can
of any suitable kind such as for example radar transceivers or
Lidar transceivers, applying a corresponding well-known technology
for transmitting and receiving reflected signals. To enable this,
according to some aspects, each detector transceiver 2a, 2b; 3a, 3b
comprises a corresponding transmitter arrangement and receiver
arrangement together with other necessary circuitry in a well-known
manner.
[0051] The detector transceivers 2a, 2b; 3a, 3b can be arranged in
many ways within the scope of the present disclosure, according to
some aspects there is a first outer detector transceiver 2a, a
second outer detector transceiver 2b, a first inner detector
transceiver 3a and a second inner detector transceiver 3b.
According to some aspects, all detector transceivers 2a, 2b; 3a, 3b
are positioned at a common horizontal level L as indicated in FIG.
4. Other position arrangements are of course conceivable.
[0052] With reference also to FIG. 2, the outer detector
transceivers 2a, 2b are associated with outer coverage main
directions 7a, 7b that are directed at corresponding outer angles
.alpha..sub.a, .alpha..sub.b to the forward traveling direction D,
and the inner detector transceivers 3a, 3b are associated with
inner coverage main directions 8a, 8b that are directed at
corresponding inner angles .beta..sub.a, .beta..sub.b to the
forward traveling direction D.
[0053] According to the present disclosure, the inner angles
.beta..sub.a, .beta..sub.b have magnitudes that exceed the
magnitudes of the outer angles .alpha..sub.a, .alpha..sub.b, and
the inner coverage main directions 8a, 8b intersect in front of the
outdoor robotic work tool 1 in the forward traveling direction D.
According to some aspects, the outer angles .alpha..sub.a,
.alpha..sub.b are of the same magnitude and the inner angles
.beta..sub.a, .beta..sub.b are of the same magnitude.
[0054] In FIG. 1, in accordance with some aspects, the outer angles
.alpha..sub.a, .alpha..sub.b are zero degrees, the outer coverage
main directions 7a, 7b being parallel and coinciding with the
forward traveling direction D. In FIG. 2, in accordance with some
aspects, the outer angles .alpha..sub.a, .alpha..sub.b have a
certain magnitude and are directed such that the outer coverage
main directions 7a, 7b do not intersect in front of the outdoor
robotic work tool 1 in the forward traveling direction D. It is
also conceivable that the outer coverage main directions 7a, 7b do
intersect in front of the outdoor robotic work tool 1.
[0055] As only shown in FIG. 1 for reasons of clarity, according to
some aspects, each coverage main direction 7a, 7b; 8a, 8b is
associated with a corresponding transceiver coverage 12a, 12b; 13a,
13b, where the associated main direction 7a, 7b; 8a, 8b indicates a
direction in which that transceiver coverage 12a, 12b; 13a, 13b has
a maximum range. A combined rectangular coverage 14, having a
certain width w, is formed in front of the outdoor robotic work
tool 1 in the forward traveling direction D, where the combined
coverage 14 comprises at least two separate transceiver coverages
12a, 12b; 13a, 13b. According to some aspects, the width w is equal
to or exceeds to a maximum width of the robotic lawn mower 1, where
said width w extends in a direction orthogonal to the forward
traveling direction D. In FIG. 1, the width w is shown to exceed
the maximum width of the robotic lawn mower 1.
[0056] By means of the relation of the coverage main directions 7a,
7b; 8a, 8b, a larger combined rectangular coverage 14, comprising
at least two separate transceiver coverages 12a, 12b; 13a, 13b, is
achieved than previously possible. This enables objects in the path
of the robotic lawn mower 1 to be detected in an efficient and
reliable manner, in particular earlier than previously possible,
such that all obstacles are detected in time such that a collision
can be avoided by stopping the robotic lawn mower 1 and/or turning
the robotic lawn mower 1 away from the obstacle.
[0057] For this purpose, as shown in FIG. 1 and FIG. 2, the robotic
lawn mower 1 comprises a control unit 18 that is adapted to control
the detector transceivers 2a, 2b; 3a, 3b and to control the speed
and direction of the robotic work tool 1 in dependence of
information acquired by means of the of the detector transceivers
2a, 2b; 3a, 3b when the robotic lawn mower 1 is moving. The control
unit 18 can be constituted by several separate control sub-units or
one single integrated control unit. The control unit 18 is adapted
to perform all necessary signal processing necessary for
controlling the detector transceivers 2a, 2b; 3a, 3b and to acquire
the desired information from the detected measurement results.
[0058] Should a collision occur anyway, at least the front body
part 20a is movable and in contact with a collision sensor 24 as
illustrated in FIG. 1 and being adapted to detect that the front
body part 20a has been displaced to such a degree that a collision
most likely has occurred. One or more collision sensors can be used
for each one body part, preferably all body parts 20a, 20b, here
only one collision sensor 24 is shown as an example. The control
unit 18 that is adapted to control the speed and direction of the
robotic work tool 1 in dependence of information from said
collision sensor 24 s well, for example to reverse the movement
direction when a possible collision has been detects.
[0059] As indicated in FIG. 2, in accordance with some aspects, the
robotic lawn mower 1 comprises a handle part 25 that is provided
for lifting and handling the robotic lawn mower 1 when necessary,
for example for service, inspection and/or cleaning. The handle
part 25 is placed closer to the ground than the detector
transceivers 2a, 2b; 3a, 3b when the robotic lawn mower 1 is
operating, and is positioned in a front recess 26 such that it does
not protrude as a frontmost part. This means that the first outer
detector transceiver 2a and the second outer detector transceiver
2b are positioned closer to a front line F of the robotic lawn
mower 1 than the first inner detector transceiver 3a and the second
inner detector transceiver 3b, and in other words, the inner
detector transceivers 3a, 3b are displaced along the forward
traveling direction D with respect to the outer detector
transceivers 2a, 2b.
[0060] As a consequence, the handle part 25 does not disturb the
operation of the inner detector transceivers 3a, 3b, and the front
recess 26 is formed such that the front body parts 20a does not
disturb the operation of the inner detector transceivers 3a, 3b,
mainly by causing unwanted reflections. By means of the present
design, a front wheel pair 17a, 17b, the so-called caster wheels
17a, 17b, can be arranged as close to the front line F as possible
and as spaced apart as possible for increased stability of the
robotic lawn mower 1.
[0061] In accordance with some further aspects of the present
disclosure, with reference to in particular FIG. 3, the detector
transceivers 2a, 2b; 3a, 3b are adapted to transmit signals 4a, 4b;
5a, 5b at the same time. This means that in the illustrated
example, where there is a first object 10 and a second object 11 in
front of the robotic lawn mower 1, the first object 10 will be
detected by the first outer detector transceiver 2a by means of a
first signal 4a transmitted by the first outer detector transceiver
2a that results in a second signal 6a, reflected from the first
object 10, that is received by the first outer detector transceiver
2a.
[0062] Furthermore, the second object 11 will be detected by the
second outer detector transceiver 2b since a third signal 5a
transmitted by the first inner detector transceiver 3a results in a
fourth signal 6b, reflected from the second object 11, that is
received by the second outer detector transceiver 2b. The second
object 11 will also be detected by the first inner detector
transceiver 3a since a fifth signal 4b transmitted by the second
outer detector transceiver 2b results in a sixth signal 9,
reflected from the second object 10, that is received by the first
inner detector transceiver 3a.
[0063] Since the detector transceivers 2a, 2b; 3a, 3b are adapted
to transmit signals 4a, 4b; 5a, 5b at the same time, detection of
reflected signals will indicate the presence of one or more objects
ahead, but not more specific details such as for example azimuth
heading and/or distance, since a signal received at one detector
transceivers can result from a signal transmitted from any one of
the detector transceivers 2a, 2b; 3a, 3b. Normally it is sufficient
for a robotic lawn mower 1 to be informed about the fact that there
is one or more objects ahead in order to avoid a collision. Should
a more specific detection be desired and/or required, each detector
transceivers 2a, 2b; 3a, 3b can be adapted to transmit specific
signals, such that a received signal can be identified with respect
to its transmitting detector transceivers 2a, 2b; 3a, 3b. Such an
identification can for example be accomplished by means of
utilizing different waveforms or embedded identifications codes for
the transmitted signals 4a, 4b, 5a, 5b.
[0064] Generally, at least two detector transceivers 2a, 2b; 3a, 3b
are adapted to transmit signals 4a, 4b; 5a, 5b and to receive
reflected signals 6a, 6b, 9 that have been reflected by an object
10, 11, where the detector transceivers 2a, 2b; 3a, 3b are adapted
to transmit signals 4a, 4b; 5a, 5b at least partly at the same
time. This means that several alternatives are possible, separately
or in combination. For example: [0065] the detector transceivers
2a, 2b; 3a, 3b always transmit signals at the same time, [0066] two
or more detector transceivers transmit signals at the same time, in
the same or in different constellations at different times, and/or
[0067] at some times, only one detector transceiver 2a, 2b; 3a, 3b
at a time transmits signals.
[0068] This means that the simultaneous transmission can be adapted
either for different need that arise in dependence of detection
results and/or in dependence of a certain predetermined
scheduling.
[0069] Having a signal transmitted by one detector transceiver 2a,
2b; 3a, 3b being detectable by any one of the detector transceivers
2a, 2b; 3a, 3b increases the possibility that an object 10, 11 in
front of the robotic lawn mower 1 is detected.
[0070] It should be noted that the second inner detector
transceiver 3b transmits a signal 5b where the transceiver coverage
13b indicated in FIG. 1 implies that the signal 5b will be
reflected by the first object 10, but where a reflected signal will
travel away from the robotic lawn mower 1 and not be detected by
any detector transceiver.
[0071] FIG. 6 schematically illustrates, in terms of a number of
functional units, the components of the control unit 18 according
to embodiments of the discussions herein. Processing circuitry 27
is provided using any combination of one or more of a suitable
central processing unit CPU, multiprocessor, microcontroller,
digital signal processor DSP, etc., capable of executing software
instructions stored in a computer program product, e.g. in the form
of a storage medium 28. The processing circuitry 27 may further be
provided as at least one application specific integrated circuit
ASIC, or field programmable gate array FPGA. The processing
circuitry thus comprises a plurality of digital logic
components.
[0072] Particularly, the processing circuitry 27 is configured to
cause the control unit 18 to perform a set of operations, or steps
to control the operation of the robotic lawn mower 1 including, but
not being limited to, controlling the detector transceivers 2a, 2b;
3a, 3b, processing measurements results received via the detector
transceivers 2a, 2b; 3a, 3b, and the propulsion of the robotic lawn
mower 1. For example, the storage medium 28 may store the set of
operations, and the processing circuitry 27 may be configured to
retrieve the set of operations from the storage medium 28 to cause
the control unit 18 to perform the set of operations. The set of
operations may be provided as a set of executable instructions.
Thus, the processing circuitry 27 is thereby arranged to execute
methods as herein disclosed.
[0073] The storage medium 28 may also comprise persistent storage,
which, for example, can be any single one or combination of
magnetic memory, optical memory, solid state memory or even
remotely mounted memory.
[0074] According to some aspects, the control unit 18 further
comprises an interface 29 for communications with at least one
external device such as a control panel 30 or an external device.
As such the interface 29 may comprise one or more transmitters and
receivers, comprising analogue and digital components and a
suitable number of ports for wireline communication. The interface
29 can be adapted for communication with other devices 34, such as
a server, a personal computer or smartphone, the charging station,
and/or other robotic working tools. Examples of such wireless
communication devices are Bluetooth.RTM., WiFi.RTM. (IEEE802.11b),
Global System Mobile (GSM) and LTE (Long Term Evolution), to name a
few.
[0075] FIG. 7 shows a computer program product 31 comprising
computer executable instructions 32 stored on media 33 to execute
any of the methods disclosed herein.
[0076] With reference to FIG. 8, the present disclosure also
relates to a method in an outdoor robotic work tool 1 adapted for a
forward traveling direction D, where the method comprises
transmitting and receiving S100 reflected signals 6a, 6b, 9 that
have been reflected by an object 10, 11 using at least two detector
transceivers 2a, 2b; 3a, 3b, and transmitting S200 signals 4a, 4b;
5a, 5b at all detector transceivers 2a, 2b; 3a, 3b at least partly
at the same time.
[0077] According to some aspects, the method further comprises
transmitting S210 signals at the same time at all detector
transceivers 2a, 2b; 3a, 3b.
[0078] According to some aspects, the method further comprises
transmitting S220 signals at the same time at two or more detector
transceivers, in the same or in different constellations at
different times.
[0079] According to some aspects, the method further comprises
transmitting S230 signals at only one detector transceiver 2a, 2b;
3a, 3b at a time at certain times.
[0080] According to some aspects, the method further comprises
transmitting S240 a signal comprising a specific signal
identification at each detector transceiver 2a, 2b; 3a, 3b, such
that a received signal can be identified with respect to its
transmitting detector transceiver 2a, 2b; 3a, 3b.
[0081] According to some aspects, the signal identification is
accomplished by means of utilizing different waveforms or embedded
identifications codes.
[0082] Generally, the present disclosure relates to an outdoor
robotic work tool 1 adapted for a forward traveling direction D and
comprising an environmental detection system 19 that comprises a
set of outer detector transceivers 2a, 2b and a set of inner
detector transceivers 3a, 3b, where the inner detector transceivers
3a, 3b are positioned between the outer detector transceivers 2a,
2b. Each detector transceiver 2a, 2b; 3a, 3b is adapted to transmit
signals 4a, 4b; 5a, 5b and to receive reflected signals 6a, 6b, 9
that have been reflected by an object 10, 11. The outer detector
transceivers 2a, 2b are associated with outer coverage main
directions 7a, 7b that are directed at corresponding outer angles
.alpha..sub.a, .alpha..sub.b to the forward traveling direction D,
and the inner detector transceivers 3a, 3b are associated with
inner coverage main directions 8a, 8b that are directed at
corresponding inner angles .beta..sub.a, .beta..sub.b to the
forward traveling direction D. The inner angles .beta..sub.a,
.beta..sub.b have magnitudes that exceed the magnitudes of the
outer angles .alpha..sub.a, .alpha..sub.b, and the inner coverage
main directions 8a, 8b intersect in front of the outdoor robotic
work tool 1 in the forward traveling direction D.
[0083] According to some aspects, each coverage main direction 7a,
7b; 8a, 8b is associated with a corresponding transceiver coverage
12a, 12b; 13a, 13b, where a combined rectangular coverage 14 having
a certain width w is formed in front of the outdoor robotic work
tool 1 in the forward traveling direction D. The combined coverage
14 comprises at least two separate transceiver coverages 12a, 12b;
13a, 13b.
[0084] According to some aspects, the outer angles .alpha..sub.a,
.alpha..sub.b are of the same magnitude and the inner angles
.beta..sub.a, .beta..sub.b are of the same magnitude.
[0085] According to some aspects, the outer coverage main
directions 7a, 7b do not intersect in front of the outdoor robotic
work tool 1 in the forward traveling direction D.
[0086] According to some aspects, the outer coverage main
directions 7a, 7b are mutually parallel.
[0087] According to some aspects, the detector transceivers 2a, 2b;
3a, 3b are adapted to transmit signals 4a, 4b; 5a, 5b at least
partly at the same time.
[0088] According to some aspects, the detector transceivers 2a, 2b;
3a, 3b are any one of radar transceivers, ultrasonic transceivers
or Lidar transceivers.
[0089] According to some aspects, the robotic work tool 1 is a
robotic lawn mower.
[0090] According to some aspects, the robotic work tool 1 comprises
a first outer detector transceiver 2a, a second outer detector
transceiver 2b, a first inner detector transceiver 3a and a second
inner detector transceiver 3b.
[0091] According to some aspects, the robotic work tool 1 comprises
a propulsion motor arrangement 15, a power source 16 adapted to
provide power to the propulsion motor arrangement 15, a plurality
of wheels 17a, 17b; 21a, 21b where at least two wheels are adapted
to be propelled by the propulsion motor arrangement 15, and a
control unit 18 that is adapted to control the detector
transceivers 2a, 2b; 3a, 3b and to control the speed and direction
of the robotic work tool 1 in dependence of information acquired by
means of the of the detector transceivers 2a, 2b; 3a, 3b when the
robotic work tool 1 is moving.
[0092] Generally, the present disclosure also relates to an outdoor
robotic work tool 1 adapted for a forward traveling direction D and
comprising an environmental detection system that comprises at
least two detector transceivers 2a, 2b; 3a, 3b that are adapted to
transmit signals 4a, 4b; 5a, 5b and to receive reflected signals
6a, 6b, 9 that have been reflected by an object 10, 11. The
detector transceivers 2a, 2b; 3a, 3b are adapted to transmit
signals 4a, 4b; 5a, 5b at least partly at the same time.
[0093] According to some aspects, the robotic work tool 1 comprises
a set of outer detector transceivers 2a, 2b, a set of inner
detector transceiver 3a, 3b, where the inner detector transceivers
3a, 3b are positioned between the outer detector transceivers 2a,
2b, where the outer detector transceivers 2a, 2b are associated
with outer coverage main directions 7a, 7b that are directed at
corresponding outer angles .alpha..sub.a, .alpha..sub.b to the
forward traveling direction D, and the inner detector transceivers
3a, 3b are associated with inner coverage main directions 8a, 8b
that are directed at corresponding inner angles .beta..sub.a,
.beta..sub.b to the forward traveling direction D, wherein the
inner angles .beta..sub.a, .beta..sub.b have magnitudes that exceed
the magnitudes of the outer angles .alpha..sub.a, .alpha..sub.b,
and where the inner coverage main directions 8a, 8b intersect in
front of the outdoor robotic work tool 1 in the forward traveling
direction D.
[0094] According to some aspects, the detector transceivers 2a, 2b;
3a, 3b are adapted to transmit signals at the same time at all
detector transceivers 2a, 2b; 3a, 3b.
[0095] According to some aspects, the detector transceivers 2a, 2b;
3a, 3b are adapted to transmit signals at the same time at two or
more detector transceivers, in the same or in different
constellations at different times.
[0096] According to some aspects, the detector transceivers 2a, 2b;
3a, 3b are adapted to transmit signals at only one detector
transceiver 2a, 2b; 3a, 3b at a time at certain times.
[0097] According to some aspects, each detector transceiver 2a, 2b;
3a, 3b is adapted to transmit a signal comprising a specific signal
identification, such that a received signal can be identified with
respect to its transmitting detector transceivers 2a, 2b; 3a,
3b.
[0098] According to some aspects, the signal identification is
accomplished by means of utilizing different waveforms or embedded
identifications codes.
[0099] The present disclosure is not limited to the above, but may
vary freely within the scope of the appended claims. For example,
each detector transceivers 2a, 2b; 3a, 3b comprises associated
well-known components such as a signal generator, a transmitting
and receiving device such as a ultrasonic emitter/receiver
arrangement or an transmitting/receiving antenna arrangement, and
receiver circuitry. Each detector transceivers 2a, 2b; 3a, 3b can
be directly controlled by the control unit 18, or comprise a
sub-controller that is controlled by, and adapted to communicate
with, the control unit 18.
* * * * *