Patent Description:
Lawn and garden vehicles are known for performing a variety of tasks. For instance, powered lawn mowers are used by both homeowners and professionals alike to maintain turf areas within a property. <CIT> discloses a method for controlling a mower through a gate opening and is background art to the invention.

Robotic mowers that autonomously perform a grass cutting function are also known. Autonomous mowers typically include a cutter housing having a cutting member or blade. A battery-powered electric motor is generally included to power both the cutting blade as well as a propulsion system. Depending on the property size, the mower may cut only a portion of the property before returning to a base station for battery re-charging.

Many properties include property barriers such as buildings, fences, and even elevational changes (e.g., terraces) that may interfere with free movement of the working machine/mower from one area of the property to another (or with exiting from or entry into a garage or other building of the property). Systems in accordance with embodiments of the present disclosure may provide autonomous working machines, systems, and methods for permitting passage of the machine through such property barrier. In some embodiments, barrier passage systems may utilize, at least in part, machine vision systems incorporated into the working machine. For example, the barrier passage system may use vision sensors associated with autonomous navigation of the machine about a work area of the property during operation. In other embodiments, however, the barrier passage system may be independent of vision and/or other machine systems.

Any aspects, embodiments, and examples of the present disclosure which do not fall under the scope of the appended claims do not form part of the invention and are merely provided for illustrative purposes.

A more complete understanding of illustrative embodiments will become apparent and appreciated by reference to the following Detailed Description of Exemplary Embodiments and claims in view of the accompanying figures of the drawing.

Exemplary embodiments will be further described with reference to the figures of the drawing, wherein:.

The figures are rendered primarily for clarity and, as a result, are not necessarily drawn to scale. Moreover, various structure/components, including but not limited to fasteners, electrical components (wiring, cables, etc.), and the like, may be shown diagrammatically or removed from some or all of the views to better illustrate aspects of the depicted embodiments, or where inclusion of such structure/components is not necessary to an understanding of the various exemplary embodiments described herein. The lack of illustration/description of such structure/components in a particular figure is, however, not to be interpreted as limiting the scope of the various embodiments in any way.

In the following detailed description of illustrative embodiments, reference is made to the accompanying figures of the drawing that form a part hereof. It is to be understood that other embodiments, which may not be described and/or illustrated herein, are certainly contemplated.

Headings provided herein are for the convenience of the reader and should not be used to limit the meaning of any text that follows the heading, unless so specified. Moreover, unless otherwise indicated, numbers expressing quantities, and terms expressing direction/orientation (e.g., vertical, horizontal, parallel, perpendicular, etc.) in the specification and claims are to be understood as being modified by the term "about. " The term "and/or" (if used) means one or all of the listed elements or a combination of any two or more of the listed elements. " is used as an abbreviation for the Latin phrase id est and means "that is. " is used as an abbreviation for the Latin phrase exempli gratia and means "for example.

Embodiments of the present disclosure provide autonomous machines, methods, and systems that permit autonomous functioning of the machine within a work region. Barrier passage systems and methods like those described herein permit the machine to autonomously pass (or be remotely-controlled) through (or over/under) a property barrier such as a fence or wall located in or near the work region. While the examples described herein illustrate the exemplary property barrier as a fence or wall, the terms "barrier" and "property barrier" may be used herein to refer to other obstacles (buildings, terraces, etc.) that divide a property. These exemplary barrier passage systems may permit a machine to move between different portions of a yard (e.g., move between different areas of a yard or different elevations of a tiered yard).

In some embodiments, the autonomous machine may learn and subsequently recognize a boundary of the work region using an onboard machine vision system and, optionally, other non-vision-based sensors. The vision system may utilize one or more cameras that together form part of a navigation system as described more fully in <CIT>.

While described as an autonomous mower, such a configuration is illustrative only as systems and methods described herein also have application to other autonomous working machines including, for example, commercial mowing products, other outdoor working machines or vehicles (e.g., debris blowers/vacuums, aerators, dethatchers, material spreaders, snow throwers, weeding machines for weed remediation mobile watering/treating vehicles), indoor working vehicles such as vacuums and floor scrubbers/cleaners (e.g., that may encounter obstacles), construction and utility vehicles (e.g., trenchers), observation vehicles, and load transportation vehicles (e.g., for hauling equipment or people). Furthermore, autonomous machines described herein may employ various types of navigation, such as random, modified random, or specific path planning, to carry out their intended functionality.

It is noted that the terms "have," "include," "comprises," and variations thereof, do not have a limiting meaning, and are used in their open-ended sense to generally mean "including, but not limited to," where the terms appear in the accompanying description and claims. Further, "a," "an," "the," "at least one," and "one or more" are used interchangeably herein. Moreover, relative terms such as "left," "right," "front," "fore," "forward," "rear," "aft," "rearward," "top," "bottom," "side," "upper," "lower," "above," "below," "horizontal," "vertical," and the like may be used herein and, if so, are from the perspective shown in the referenced figure, or while the machine (e.g., mower <NUM>) is in an operating configuration (e.g., while the machine is positioned such that wheels <NUM> and <NUM> rest upon a generally horizontal ground surface <NUM> as shown in <FIG>). These terms are used to simplify the description, however, and not to limit the interpretation of any embodiment described. Further, the terms "determine" and "estimate" may be used interchangeably herein.

As used herein, "property" is defined as a geographic region (such as a yard) circumscribed by a fixed boundary within which the machine <NUM> may perform work (e.g., mow grass). For example, <FIG> illustrates an exemplary property or yard <NUM> defined by a boundary <NUM> (boundary only partially illustrated). "Work region" (see, e.g., work region <NUM> in <FIG>) is used herein to refer to those areas contained (or mostly contained) within the boundary <NUM> within which the vehicle will perform work. For example, work regions could be defined by grass surfaces of the property or yard <NUM> upon which the autonomous lawn mower will perform its maintenance function (e.g., cut grass). A property may contain one or more work regions including, for example, a front-yard area and a back-yard area, or two yard areas separated by a fence (see, e.g., fence <NUM> in <FIG>). "Exclusion zone" is defined herein as an area contained within the property/work region in which the machine is not intended to perform its intended maintenance task (e.g., not intended to mow grass). Examples of exclusion zones include landscaped or garden areas such as area <NUM> shown in <FIG>, buildings, sidewalks, driveways, and other yard features. "Transit zones" may be used herein to refer to paths through exclusion zones that the machine may take when travelling between different work regions of the property. Typically, the machine will not perform a maintenance task (mowing) when moving through a transit zone.

While the construction of the actual working machine is not necessarily central to an understanding of embodiments of this disclosure, <FIG> schematically illustrates an exemplary autonomous working machine configured as an autonomous lawn mower <NUM> (also referred to herein as "machine" or "robot"), which forms part of a lawn mowing system that may include other components such as a charging station <NUM>. As shown in <FIG>, the mower <NUM> may include a housing <NUM> (e.g., frame or chassis with a shroud) that carries and/or encloses various components of the mower as described below. The mower <NUM> may further include ground support members, such as wheels, rollers, skids, or tracks. In the illustrated embodiment, the ground support members include one or more rear wheels <NUM> and one or more front wheels <NUM>, that support the housing <NUM> upon the ground (grass) surface <NUM>. As illustrated, the front wheels <NUM> are used to support a front-end portion <NUM> of the housing <NUM> and the rear wheels <NUM> are used to support a rear-end portion <NUM> of the mower housing.

One or both rear wheels <NUM> may be driven by a propulsion system (e.g., including one or more wheel motors <NUM>) to propel the mower <NUM> over the ground surface <NUM>. In some embodiments, the front wheels <NUM> may freely caster relative to the housing <NUM> (e.g., about vertical axes). In such a configuration, mower direction may be controlled via differential rotation of the two rear wheels <NUM> in a manner similar to a conventional zero-turn-radius (ZTR) riding mower. That is to say, the propulsion system may include a separate wheel motor <NUM> for each of a left and right rear wheel <NUM> (see <FIG>) so that speed and direction of each rear wheel may be independently controlled. In addition, or alternatively, the front wheels <NUM> could be actively steerable by the propulsion system (e.g., including one or more steer motors <NUM>) to assist with control of mower <NUM> direction, and/or could be driven by the propulsion system (i.e., to provide a front-wheel or all-wheel drive mower).

An implement or tool (e.g., a grass cutting element, such as a blade <NUM>) may be coupled to a cutting motor <NUM> carried by the housing <NUM>. When the motors <NUM> and <NUM> are energized, the mower <NUM> may be propelled over the ground surface <NUM> such that vegetation (e.g., grass) over which the mower passes is cut by the rotating blade <NUM>. While illustrated herein using only a single blade <NUM> and/or cutting motor <NUM>, mowers incorporating multiple blades, powered by single or multiple motors, are contemplated within the scope of this disclosure. Moreover, while described herein in the context of one or more conventional "blades," other cutting elements including, for example, disks, nylon string or line elements, knives, cutting reels, etc., are certainly possible without departing from the scope of this disclosure. Still further, embodiments combining various cutting elements, e.g., a rotary blade with an edge-mounted string trimmer, are also contemplated.

The mower <NUM> may further include a power source, which in one embodiment, is a battery <NUM> having a lithium-based chemistry (e.g., lithium-ion). Other embodiments may utilize batteries of other chemistries, or other power source technologies (e.g., solar power, fuel cell, internal combustion engines) altogether, without departing from the scope of this disclosure. It is further noted that, while shown as using independent blade and wheel motors, such a configuration is illustrative only as embodiments wherein blade and wheel power is provided by a single motor are also contemplated.

The mower <NUM> may further include one or more sensors to provide location data. For instance, some embodiments may include a global positioning system (GPS) receiver <NUM> (or other position sensor that may provide similar data) that is adapted to estimate a position of the mower <NUM> within the work region and provide such information to an electronic machine controller <NUM> (described below) associated with the working machine (mower <NUM>) that, among other uses, is adapted to autonomously control navigation of the machine as the machine traverses the property/work region divided by or otherwise containing the property barrier. In other embodiments, one or more of the wheels <NUM>, <NUM> may include encoders <NUM> that provide wheel rotation/speed information (odometry) that may be used to estimate mower position (e.g., based upon an initial start position) within a given work region. The mower <NUM> may also include a sensor <NUM> adapted to detect a boundary wire, which could be used in addition to vision-based navigational techniques.

The mower <NUM> may optionally include one or more front obstacle detection ("bump") sensors <NUM> and one or more rear obstacle detection sensors <NUM>, as well as other sensors, such as side obstacle detection sensors (not shown). The obstacle detection sensors <NUM>, <NUM> may be used to detect an obstacle in the path of the mower <NUM> when travelling in a forward or reverse direction, respectively (the mower <NUM> may be capable of mowing while moving in both forward and reverse directions). As illustrated, the sensors <NUM>, <NUM> may be located at the front-end portion <NUM> and rear-end portion <NUM> of the mower <NUM>, respectively. In addition to the sensors described, other sensors now known or later developed may also be incorporated into the mower <NUM>.

The mower <NUM> carries or otherwise includes one or more cameras to provide localization data, such as position, orientation, and/or velocity. The cameras may include two or more cameras <NUM> carried by the working machine (mower) and operatively coupled or otherwise in communication with the machine controller <NUM> that capture or record digital image data for use with a vision system associated with the machine controller <NUM>. That is, the cameras <NUM> may be described as part of the vision system of the mower <NUM>. Types of image data include, for example, training image data and/or operational image data.

The one or more cameras may be capable of detecting visible light, non-visible light, or both. The one or more cameras may establish a total field of view of at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, or even <NUM> degrees, around the autonomous machine (e.g., mower <NUM>). The field of view may be defined in a horizontal direction, a vertical direction, or both directions. For example, a total horizontal field of view may be <NUM> degrees, and a total vertical field of view may be <NUM> degrees. The field of view may capture image data above and below the height of the one or more cameras.

In some embodiments, the mower <NUM> includes four cameras <NUM> (e.g., cameras <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>; collectively and individually referred to as camera or cameras <NUM>) as shown in <FIG>. One camera <NUM> may be positioned in each of one or more directions including a forward direction (camera <NUM>-<NUM>), a reverse direction (camera <NUM>-<NUM>), a first (e.g., left) side direction (camera <NUM>-<NUM>), and a second (e.g., right) side direction (camera <NUM>-<NUM>), thereby forming Cardinal directions relative to the mower <NUM>. One or more camera directions may be positioned orthogonal to one or more other cameras <NUM> or positioned opposite to at least one other camera <NUM>. Although not shown, the cameras <NUM> may also be offset from any of these directions (e.g., at a <NUM> degree or another non-right angle).

The mower <NUM> includes the machine controller <NUM> (see <FIG>) adapted to monitor and control various mower functions. The machine controller <NUM> may include a processor <NUM> that receives various inputs and executes one or more computer programs or applications stored in memory <NUM>. The memory <NUM> may include computer-readable instructions or applications that, when executed, e.g., by the processor <NUM>, cause the machine controller <NUM> to perform various calculations and/or issue commands. That is to say, the processor <NUM> and memory <NUM> may together define a computing apparatus operable to process input data and generate the desired output to one or more components/devices. For example, the processor <NUM> may receive various input data including positional data from the GPS receiver <NUM> and/or wheel encoders <NUM> and generate speed and steering angle commands to the wheel motor(s) <NUM> to cause the rear wheels <NUM> to rotate (at the same or different speeds and in the same or different directions). In other words, the machine controller <NUM> may control the steering angle and speed of the mower <NUM>, as well as the speed and operation of the cutting blade <NUM>.

Reference herein may be made to various parameters, data, or data structures, which may be handled in the machine controller <NUM>, for example, by being processed by the processor <NUM> or stored in or retrieved from the memory <NUM>. The machine controller <NUM> may use the processor <NUM> and memory <NUM> in different systems. Alternatively, one or more processors <NUM> and memory <NUM> may be included in each different system. In some embodiments, the machine controller <NUM> may form part of a vision system, which may include a processor <NUM> and memory <NUM>. The machine controller <NUM> may also at least partially define a navigation system, which may also include a processor <NUM> and memory <NUM> the same or separate from the processor <NUM> and memory <NUM> of the vision system. In general, as used herein, the term "controller" may be used to describe components of a system that receive inputs and provide outputs and commands to control various other components of a system.

A communication system <NUM> may be provided to permit the mower <NUM>/machine controller <NUM> to operatively communicate (e.g., via a wireless radio <NUM>) with a communication network that may include a wireless network <NUM>, thereby allowing communication (e.g., bidirectional communication) between the mower and other devices. For example, the wireless network <NUM> may be a cellular or other wide area network, a local area network (e.g., Institute of Electrical and Electronics Engineers (IEEE) <NUM> local "Wi-Fi" network), or a personal area or peer-to-peer network ("P2P," e.g., "Bluetooth" network). Other devices may communicate over the wireless network with the mower <NUM>, including, for example, a remote computer <NUM>, which may be configured as a cellular phone, tablet, desktop computer, notebook computer, or wearable computer. Preferably, the wireless network <NUM> is connected to the internet so that the user/remote computer <NUM> may interact with the communication system <NUM> regardless of the user's location. Moreover, connection of the wireless network <NUM> to the internet allows communication with most any other remote computer including, for example, an internet (cloud)- connected server <NUM>.

The communication system <NUM> may also permit communication over the wireless network with a gate receiver (see, e.g., wireless receiver(s) <NUM> in <FIG>) as further described below. Although not specifically illustrated, the communication system <NUM> may further include conventional network hardware including gateways <NUM>, routers, wireless access points, etc. (not shown).

While illustrated as using a centralized communication network (e.g., wherein each device connects to a central network), other embodiments may utilize a decentralized or ad-hoc network, wherein communication occurs directly between devices. For example, the mower may communicate directly with the wireless receiver <NUM> as further described below rather than communicate indirectly over the wireless network <NUM>. Still further, while illustrated as primarily utilizing wireless communication protocols, such a configuration is not limiting as for example, various devices (e.g., the charging station <NUM> and/or the gateway <NUM>) could connect to the communication network or other devices using wired connections without departing from the scope of this disclosure.

It will be readily apparent that the functionality of the machine controller <NUM> may be implemented in any manner known to one skilled in the art. For instance, the memory <NUM> may include any volatile, non-volatile, magnetic, optical, and/or electrical media, such as a random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, and/or any other digital media. While shown as both being incorporated into the machine controller <NUM>, the memory <NUM> and the processor <NUM> could be contained in separate modules.

The processor <NUM> may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and/or equivalent discrete or integrated logic circuitry. In some embodiments, the processor <NUM> may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, and/or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to the machine controller <NUM> and/or processor <NUM> herein may be embodied as software, firmware, hardware, or any combination of these. Certain functionality of the machine controller <NUM> may also be performed in the "cloud" (e.g., at the server <NUM>) or other distributed computing system operatively connected to the processor <NUM>.

In <FIG>, schematic connections are generally shown between the machine controller <NUM> and the battery <NUM>, wheel motor(s) <NUM>, cutting motor <NUM>, optional boundary wire sensor <NUM>, wireless radio <NUM>, and GPS receiver <NUM>. This interconnection is illustrative as the various subsystems of the mower <NUM> could be connected in most any manner, e.g., directly to one another, wirelessly, via a bus architecture (e.g., controller area network (CAN) bus), or any other connection configuration that permits data and/or power to pass between the various components of the mower. Although connections with some of the sensors <NUM>, <NUM>, and <NUM> are not shown, these sensors and other components of the mower <NUM> may be interconnected in a similar manner.

In some embodiments, various functionality of the machine controller <NUM> described herein may be offloaded from the mower <NUM>. For example, recorded image data may be transmitted to a remote server (e.g., an internet-connected server <NUM>) using the wireless radio <NUM> and then processed or stored. Alternatively, some functionality of the machine controller <NUM> may be provided by components on the charging station <NUM> and/or the remote computer <NUM>.

The mower <NUM> may utilize the exemplary vision and navigation systems to permit autonomous operation of the mower within a given work region(s). For more information regarding exemplary operation and navigation of the mower <NUM>, see <CIT>.

According to the invention the mower <NUM> (see <FIG>) includes a wireless transmitter or transceiver <NUM> (that may or may not be part of the wireless radio <NUM> (see <FIG>)) that, along with the machine controller <NUM>, forms part of an autonomous barrier passage system, embodiments of which are described below. For example, <FIG> illustrates an exemplary barrier passage system ("system") <NUM> configured to permit the working machine (mower <NUM>) to cross a barrier defined by a fence <NUM> having a gate opening <NUM> formed therein. A gate <NUM> associated with the property barrier may selectively block the gate opening <NUM>. That is, the gate <NUM> may be movable between a closed position, wherein a gate opening through the property barrier is selectively blocked by the gate, and an open position, wherein passage of the working machine through the gate opening <NUM> is permitted. The gate <NUM> may be a conventional, vertical hinge gate as is known in the art, e.g., a gate that may pivot between the closed position (wherein the gate opening <NUM> through the barrier (fence) is blocked by the gate as shown by the solid line gate in <FIG>), and one or more open positions (one of which is shown by a broken representation of the gate <NUM> in <FIG>).

The system <NUM> may include an actuator <NUM>, e.g., an electric linear actuator, that is attached both to a fixed portion <NUM> (e.g., top edge) of the fence <NUM> and to an arm <NUM> attached to the gate <NUM>. The actuator is adapted to move the gate between the closed position and the open position. That is, as the actuator extends and retracts, it causes the gate to pivot, about a vertical hinge axis <NUM>, between the closed position and one or more open positions.

The actuator <NUM> (and gate controller <NUM> described below) may be connected to, and be powered by, either or both of an alternating current (AC) source or a direct current (DC) source. For example, the current source <NUM> may be a battery, solar cell, or a combination thereof. Alternatively, the current source could be a low voltage transformer <NUM> (which may be independent or part of another system (e.g., landscape lighting system, irrigation system, mower's own charging station)).

The system <NUM> includes a gate controller <NUM> adapted to selectively energize the actuator (linear actuator <NUM>) to control a position of the actuator and thus a position of the gate <NUM>. That is, the gate controller <NUM> may command the actuator <NUM> to move the gate from the closed position, wherein passage of the working machine <NUM> through the gate opening <NUM> is blocked, to an open position, wherein passage of the working machine through the gate opening is permitted. The gate controller <NUM> comunicates with the machine controller <NUM> of the mower <NUM> (see <FIG>) via any acceptable wireless protocol such that the gate can be automatically opened when the mower requests passage and closed once the mower has traversed the fence barrier.

For instance, in some embodiments the machine controller <NUM> is configured to (via the transceiver <NUM>) wirelessly transmit a gate open signal <NUM> to the gate controller <NUM> (via the wireless receiver <NUM>) as the mower approaches the gate. Such signal <NUM> may be infrared, acoustical, or radio frequency. The system <NUM> may include the wireless receiver(s) <NUM> adapted to receive the gate open signal <NUM> and communicate the same to the gate controller <NUM>, wherein the gate open signal <NUM> effectively requests movement of the working machine through the gate opening. Upon receipt of the gate open signal, the gate controller <NUM> commands the actuator <NUM> to move the gate from the closed position to the open position. (e.g., extend or retract the actuator <NUM>). The machine <NUM> may then propel autonomously through the gate opening <NUM> under control of the machine controller <NUM>. In some embodiments, the system may also wirelessly transmit a gate close signal (again, see signal <NUM>) from the machine controller <NUM> to the gate controller <NUM> after the working machine <NUM> has passed through the gate opening to effect closing of the gate <NUM>.

The system <NUM> may be configured to minimize the time period that the gate <NUM> is open to reduce the opportunity for unknown objects <NUM> (e.g., pets and other animals) to also pass through the gate. The mower <NUM> monitors an area adjacent to the gate with the cameras (see, e.g., camera(s) <NUM> in <FIG>) that operatively communicate with the machine controller <NUM>. If during this monitoring an unknown object <NUM> such as a pet or other animal is detected within the area adjacent to the gate (detected using the camera and machine controller), the system <NUM> delays movement of the gate to the open position based upon this detected presence of the unknown object. In other embodiments, the mower <NUM> (e.g., the machine controller <NUM>) may communicate with the gateway <NUM> of the communication network (e.g., wireless network <NUM>) such that the mower is effectively in communication with the associated remote computer <NUM> (e.g., a mobile phone) and other connected devices. As a result, when the mower approaches the gate <NUM>, the mower may send an alert to the user (e.g., to the user's mobile phone) via the gateway <NUM> requesting that the gate be opened. In response, the user could remotely command the gate to open (again, via interaction with an application on the mobile phone) and allow passage of the mower through the gate opening. Alternatively, the gate could open automatically and provide a notification to the user of the same (e.g., a notification that the gate was opened and/or closed). Thus, in addition to direct communication between the mower <NUM> and the gate <NUM>, some embodiments may provide indirect communication between these two components by allowing each to communicate directly over the communication network (e.g., wireless network <NUM>).

To permit the system to detect unknown objects <NUM> such as pets or other animals, the system <NUM> (e.g., machine controller <NUM>) may utilize computer vision algorithms and machine learning to recognize objects within digital images captured by the cameras <NUM> (see <FIG>). As used herein, "object recognition" may be used to refer to various computer vision capabilities for identifying objects within a digital image. These computer vision capabilities may include algorithms for: image classification; object localization; object segmentation; and object detection.

In image classification, the system <NUM> may analyze an image and classify the image into one or more various categories (i.e., determining what is contained within the image). For example, image classification algorithms may classify an image as containing a human body or face, a dog, a tree, a fallen limb, etc. Object localization and segmentation may go a step further by, in addition to classifying the image, locating the detected object at a specific location within the image and delineating the same with a bounding box or, in the case of object segmentation, creating a pixel-by-pixel mask of the object. By iteratively applying classification and localization/segmentation algorithms to an image, object detection may yield a list of object classifications present in the image, as well as a bounding box or mask indicating the location and scale of each object.

As used herein, "unknown objects" refers to those objects within the work region (or within a local area of operation within the work region) detected by the machine controller <NUM> via the camera <NUM> (or by a remote camera), but for which the machine controller does not expect the mower <NUM> (e.g., based upon previous training) to encounter. Examples of unknown objects include but are not limited to humans, pets, wild animals, other yard vehicles, fallen branches, and debris. Unknown objects may include moving and/or stationary objects. The machine controller <NUM> may respond differently when encountering different unknown objects. For example, the machine controller <NUM> may be able to determine that the unknown object is an animal and cause different behavior than if the unknown object is determined to be something else such as a person.

The actuator <NUM> may include an encoder or other sensor adapted to generate a signal indicative of the position and movement direction of the actuator and provide the same to the gate controller <NUM>. Alternatively, other sensors (e.g., proximity sensor) may be provided on the gate and/or the fence to provide a signal when the gate <NUM> is at certain locations (e.g., in the closed position). Once the mower has moved past the gate, the gate controller <NUM> may command the actuator <NUM> to close the gate. The determination of when to close the gate after mower passage may be based upon various factors. For instance, the gate could remain open for a period of time (e.g., a period of time that adequately allows the mower <NUM> to traverse the gate opening <NUM> and get clear of the closing gate), after which the system may return the gate, via the gate controller and the actuator, to the closed position. That is, the gate may be closed after expiration of a predetermined period of time from the time the gate was opened. Alternatively, the transceiver <NUM> may transmit a gate close signal to the wireless receiver <NUM> once the mower has cleared the gate. Regardless of the gate closing process, the gate <NUM> may be held in its closed position either by the actuator <NUM> itself, or via a latch (not shown). While not illustrated, other sensors may be provided to minimize or prevent contact with unknown objects during gate closure and opening by ensuring the area around the gate is clear before gate movement.

A benefit of the system <NUM> is that it allows an existing, conventional gate to be retrofitted with the necessary components, e.g., actuator <NUM>, to allow remote and/or autonomous cooperation of the gate with the mower <NUM>. However, such a configuration is not limiting. For instance, other embodiments may provide a dedicated (e.g., "mower only") gate such as the barrier passage system <NUM> illustrated in <FIG> and <FIG>. Like the system <NUM>, the system <NUM> includes the mower <NUM> (or at least the machine controller <NUM> and transceiver <NUM>) and a barrier (e.g., a fence <NUM>) having a gate opening <NUM> formed therein, the opening selectively covered by a gate <NUM>. However, the gate <NUM> may be configured as a dedicated portal (providing intended passage only for the mower <NUM>) through the fence rather than a primary fence gate like the gate <NUM> of <FIG>. While such dedicated gates have the disadvantage of requiring modification to the actual fence structure, they also permit the gate to be located at most any position along the fence barrier. Moreover, dedicated gates are potentially smaller and more discrete, and may have the added benefit of minimizing unintended animal passage when compared to conventional gate concepts like that of <FIG>.

As shown in <FIG>, the exemplary gate <NUM> may pivot bi-directionally about a horizontal hinge line <NUM> in a manner similar to a horizontally-mounted saloon-style door. The gate <NUM> may be biased to the closed position shown in <FIG> by biasing elements, or merely by gravity. The system <NUM> may further include a gate latch <NUM> (also referred to herein merely as "latch") operable to positively secure the gate <NUM> in the closed position. For example, in one embodiment, the latch <NUM> may be configured as a solenoid-operated pin secured to one of the fence and the gate. The pin may be retracted to unlatch and extended to latch the gate. The solenoid, which may be controlled by a gate controller <NUM>, may be powered in a manner similar to the actuator <NUM> of the system <NUM>, e.g., via a battery (not shown) or a solar cell <NUM>, or via an AC or DC power supply <NUM>.

As the mower <NUM> approaches the gate <NUM>, the transceiver <NUM> (or other device(s) of the mower <NUM>) may communicate (directly or indirectly) with a receiver <NUM> on the fence/gate, and a corresponding signal provided to the gate controller <NUM>. The gate controller may then command the latch <NUM> to unlock (e.g., retract the pin). Once the latch is unlocked, the mower <NUM> may drive through the opening formed by the gate, using the propulsion force of the mower to manually displace the gate (see, e.g., broken line centerlines of gate <NUM> in open positions in <FIG>) during passage. Alternatively, the gate <NUM> may include an actuator like the actuator <NUM> described above to move the gate from the closed position (see. <FIG>) to an open position (see broken line gate centerline positions in <FIG>), in which case the latch may be unnecessary.

As an alternative to the power sources described above, the system <NUM> could also utilize a power source located on the mower (e.g., the battery <NUM> of <FIG>) to power the latch <NUM> and/or gate controller <NUM>. That is, in some embodiments, the actuator and/or the gate controller are adapted to receive electrical power from the working machine itself. For instance, the mower <NUM> may include contacts <NUM> adapted to electrically communicate (abut) corresponding contacts on the charging station <NUM> (see <FIG>) during a mower re-charging process. In the embodiments illustrated in <FIG> and <FIG>, the contacts <NUM> may also be used to engage contacts <NUM> on the gate <NUM> or fence <NUM>. Once contact is made, the battery <NUM> (see <FIG>) may charge a capacitor <NUM> or other energy storage device to a threshold level. Once that level is reached, the mower <NUM> may reverse, thus disengaging the contacts <NUM> from <NUM>. With the capacitor charged, the mower may communicate as already described herein with the gate controller <NUM>, allowing the latch to be disengaged as needed to permit passage of the mower. The gate controller <NUM> may command the solenoid to retract for a threshold time period, after which the pin may again extend. The time period may be selected to allow the mower to pass through the gate and for the door to return by gravity to equilibrium in its closed position. Alternatively, a sensor (not shown) may detect when the gate has returned to its closed position, after which the latch may engage.

<FIG> illustrates a barrier (gate) passage system <NUM> in accordance with yet another embodiment of the disclosure. The barrier may again be formed by a fence <NUM> having a gate <NUM> that selectively opens and closes a gate opening <NUM>. Like the gate <NUM>, the gate <NUM> is a dedicated portal intended for mower-only passage. However, unlike the gates described elsewhere herein, the gate <NUM> is defined by a turntable formed by a floor sector or segment <NUM> and two upwardly extending walls <NUM>. While shown as a <NUM>-degree segment in the illustrated embodiments, such a construction is exemplary only. The segment may be bound by the two upwardly extending walls <NUM> (a wall <NUM>-<NUM> and wall <NUM>-<NUM>), either of which may effectively form the actual gate as the turntable moves between a first position (shown in solid lines in <FIG>) and a second position (rotated <NUM> degrees in the direction <NUM> about a pivot axis <NUM> as indicated in broken lines). The system <NUM> may, like the system <NUM>, include an actuator (which may be a rotary actuator <NUM>), gate controller <NUM>, power source, receiver <NUM> and other components (not shown) as already described herein.

During operation, the mower <NUM> may approach the gate and park upon the surface of the floor segment <NUM>. Again, the mower <NUM> (machine controller <NUM>) may communicate with a receiver <NUM> associated with a gate controller <NUM> to indicate when the mower is in the appropriate position upon the turntable prior to passage through the fence <NUM>. As shown in <FIG>, the wall <NUM>-<NUM> may initially block the gate opening <NUM> when the mower <NUM> approaches the gate from a first side <NUM> of the gate <NUM>/fence <NUM>.

Once the mower <NUM> is so positioned, the gate controller <NUM> may command the actuator <NUM> to rotate, causing the turntable to rotate about the pivot axis <NUM>. As the gate <NUM> rotates, the floor segment <NUM> of the turntable (and accordingly the mower <NUM>) is repositioned to an opposite second side <NUM> of the fence <NUM>. After rotation of <NUM> degrees, the wall <NUM>-<NUM> now extends to the second side <NUM> of the fence (on the opposite side of the fence from first side <NUM>) and the wall <NUM>-<NUM> now closes the gate opening, minimizing ingress/egress of pets and other animals through the gate <NUM>. The gate may then stay in the rotated position until the mower returns to the gate seeking passage back to the first side <NUM> of the fence. The mower <NUM> (machine controller <NUM>) and/or the gate controller <NUM> may include logic that allows the gate to operate (rotate) without the mower in place if such rotation is needed (e.g., if the mower is approaching the gate from a side opposite the location of the floor segment <NUM>, the gate may be commanded to first rotate in order to allow the mower to access the turntable). In some embodiments, the turntable may function as a charging station for the mower. In such a configuration, one or both of the walls <NUM> may include electrical contacts (see, e.g., contacts <NUM> in <FIG>) that are operable to engage contacts (e.g., contacts <NUM>) of the mower during re-charging.

<FIG> illustrates another embodiment of a barrier (gate) passage system <NUM> in accordance with embodiments of the present disclosure. As shown in this view, the system <NUM> may include a gate module (which may define a gate like the gate <NUM> or <NUM> described above) that may be positioned (temporarily or semi-permanently) between the fence <NUM> and a partially opened, existing gate <NUM> as shown. Such a construction would allow implementation of a gate passage system without requiring modification of original gate/fence structure.

<FIG> illustrates another barrier passage system <NUM> in accordance with embodiments of the present disclosure. As shown in this view, the system <NUM> may include a gate module including a fence <NUM> and a gate <NUM> configured to open and close to permit selective passage of the mower <NUM> through a gate opening <NUM>. Like the gate <NUM>, the gate <NUM> may be a conventional, vertical hinge gate that may pivot about a vertical hinge or pivot axis <NUM> between a closed position (shown in solid lines in <FIG>) and one or more open positions (generally referred to as "open position" and represented by the partial dashed gate <NUM> in <FIG>). In the open position, a gate opening <NUM> through the fence <NUM> is presented, allowing passage of the machine/mower <NUM> therethrough.

The gate <NUM> may include a gate latch <NUM> configured to releasably secure the gate <NUM> relative to the fence <NUM> in the closed position. The gate latch <NUM> may include a retractable pin <NUM> operatively attached to the gate and a receiver <NUM> operatively attached to the fence <NUM>, wherein the retractable pin and latch may be aligned when the gate is in the closed position. As further described below, the retractable pin <NUM> may be retracted away from the receiver <NUM> to a retracted position to unlatch the gate and permit movement of the gate to the open position. Similarly, the retractable pin <NUM> may be extended toward the receiver <NUM> to an extended position as shown in <FIG> to latch the gate <NUM> in the closed position. The gate latch <NUM> may include a biasing member (e.g., spring <NUM>) to bias the retractable pin <NUM> to the extended position. While the retractable pin <NUM> is shown attached to the gate <NUM> and the receiver <NUM> to the fence <NUM>, such a configuration is exemplary only.

The system <NUM> may further include an actuator <NUM>, which may be configured as an electric motor attached to the fence <NUM>. An actuator cable <NUM> may be coupled to the actuator, wherein the actuator cable extends through an offset cable guide <NUM>. The actuator cable <NUM> has a first end <NUM> coupled to the retractable pin <NUM> of the gate latch <NUM> and a second end <NUM> coupled to the actuator <NUM> so that the actuator is effectively coupled to the retractable pin. The actuator <NUM> may be employed to extend and retract the actuator cable <NUM> to pivot the gate <NUM> between the closed and open positions, respectively, as further described below. The system <NUM> may, like the system <NUM>, include a gate controller, a power source, a receiver, and other components (not shown) as already described herein above.

The actuator cable <NUM> may extend through, or along, the cable guide <NUM>, the latter being an elongate member operatively positioned between the actuator <NUM> and the gate latch <NUM>. The exemplary cable guide <NUM> may include a proximal or first end <NUM> coupled to the fence/gate such that the cable guide may pivot about the vertical pivot axis <NUM>. The cable guide <NUM> may further include an offset distal or second end <NUM>. Located at or near the second end <NUM> is a hole or aperture <NUM> through which the actuator cable <NUM> may pass.

The cable guide <NUM> may pivot about the vertical pivot axis <NUM> from a first position (e.g., shown in solid lines in <FIG>) wherein the cable guide is generally perpendicular to the fence <NUM>), to a second position between perpendicular and parallel to the fence <NUM> (e.g., between <NUM> degrees to <NUM> degrees to the fence <NUM> as indicated by the alternative broken line representations of the cable guide <NUM> in <FIG>, and in a gate fully open position as illustrated in <FIG>), as indicated by direction <NUM>, in response to retraction of the actuator cable <NUM> by the actuator <NUM>. The cable guide <NUM> is thus adapted to provide an offset moment arm for the force applied by the actuator cable <NUM> to the gate <NUM>. This offset permits the cable to pivot the gate <NUM> about the vertical hinge axis <NUM> as indicated by arrow <NUM>. The cable guide <NUM> may be configured of any suitable material such as metal or polyvinyl chloride (PVC), and may be of cylindrical, rectangular, or most any other cross-sectional shape.

In some one embodiments, a pair of biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> (e.g., springs) may be provided and adapted to act upon the cable guide <NUM>. For example, the system <NUM> may include a first biasing mechanism <NUM>-<NUM> operatively positioned between the cable guide <NUM> and the gate <NUM>, and a second biasing mechanism <NUM>-<NUM> operatively positioned between the cable guide and the fence <NUM>. The pair of biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> can apply biasing forces to the cable guide <NUM> (in opposing pivotal directions) about the vertical pivot axis <NUM>. As a result, the biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> can assist in the pivotal movement of both the cable guide <NUM> and the gate <NUM>. For example, the biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> may be configured to: bias the cable guide <NUM> to the first position (e.g., perpendicular to the fence <NUM> to provide the desired offset of the cable); and, correspondingly, the gate to the closed position.

The system <NUM> may also include one or more cable eyes <NUM> positioned between the cable guide <NUM> and the gate latch <NUM>. The cable eye(s) <NUM> may serve as a guide(s) for the actuator cable <NUM> to permit effective manipulation of the gate latch <NUM>. For instance, the cable eye <NUM> may be attached to the gate <NUM> between the retractable pin <NUM> and the vertical pivot axis <NUM> such that the actuator cable <NUM> extends generally parallel to the gate <NUM> between the retractable pin <NUM> and the cable eye <NUM>. As a result, the actuator cable <NUM> may be optimally oriented for longitudinal movement of the retractable pin <NUM> (in the direction <NUM>) in response to a force applied by the actuator cable <NUM>.

The actuator <NUM> can initiate retraction of the actuator cable <NUM> in response to a gate open signal from the mower <NUM> to open the gate <NUM> (said signal received by the gate controller via a receiver as already described herein). As the actuator cable <NUM> is retracted, the retractable pin <NUM> of the gate latch <NUM> is slidably moved parallel to the gate <NUM> in response to the force applied by the cable to transition the retractable pin <NUM> from the extended position (illustrated in solid lines in <FIG>) to the retracted position (illustrated in broken lines). As the actuator cable <NUM> continues to retract, the retractable pin <NUM> eventually "bottoms out" such that further retraction of the cable begins to pivot the gate <NUM> away from its closed position. As the cable retracts and the gate pivots, the cable guide <NUM> may pivot in the same direction (e.g., in the direction <NUM> toward the actuator <NUM>) due to the force resulting from compression of the biasing mechanism <NUM>-<NUM>. In some embodiments, the biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> may seek to equalize their biasing forces, effectively causing the cable guide to extend from the vertical pivot axis <NUM> at an angle that is half-way between the fence <NUM> and the gate <NUM>. For example, the cable guide <NUM> may be perpendicular to the fence <NUM> when the gate is in the closed position and extend at an angle of <NUM> degrees to the fence (see broken line rendering of the cable guide <NUM> in <FIG>) when the gate opens <NUM> degrees from its closed position.

To close the gate <NUM>, the actuator <NUM> may reverse directions and extend the actuator cable <NUM>. As the actuator cable <NUM> extends, the biasing forces applied by the biasing mechanisms <NUM>-<NUM>, <NUM>-<NUM> may assist in pivoting the cable guide <NUM> back to the first position and, correspondingly, the gate <NUM> back to the closed position. As the actuator cable <NUM> continues to extend, the cable releases the retractable pin <NUM> of the gate latch <NUM>, whereby the biasing force applied by the spring <NUM> returns the retractable pin <NUM> to the extended position, effectively securing the gate in the closed position.

As stated above, while shown in the context of a fence barrier, embodiments of the present disclosure may find application to most any property barrier including, for example, building (garage, shed) ingress/egress. Moreover, while shown as manipulating a swinging gate of some kind to permit mower passage, other barrier passage systems may permit the mower to travel under (or over the fence) without departing from the scope of this disclosure. Moreover, a gate that translates upwardly, downwardly, or to a side to move to the open position is also contemplated.

Some properties may utilize multiple fences and/or multiple gates. In such cases, each gate may include a unique electronic signature or visual indicia (see, e.g., indicia <NUM> in <FIG>) that the mower may recognize (e.g., via the cameras <NUM>) to confirm that the mower <NUM> is at or near a specific gate.

Claim 1:
A method for controlling operation of an autonomous working machine (<NUM>) through a gate opening (<NUM>) formed through a property barrier (<NUM>), the gate opening selectively blocked by a gate (<NUM>), the method comprising:
approaching a first side of the gate with the working machine, the working machine comprising:
a machine controller (<NUM>) adapted to autonomously control navigation of the working machine as the working machine traverses a property containing the property barrier; and
one or more cameras carried by the working machine and in communication with the machine controller;
wirelessly transmitting a gate open signal from the machine controller to a gate controller (<NUM>) associated with the gate;
commanding, via the gate controller, an actuator (<NUM>) connected to the gate to move the gate from a closed position, wherein passage of the working machine through the gate opening of the property barrier is blocked, to an open position, wherein passage of the working machine through the gate opening of the property barrier is permitted;
monitoring an area adjacent to the gate with the one or more cameras;
detecting an unknown object (<NUM>) within the area adjacent to the gate using the one or more cameras and machine controller;
delaying movement of the gate to the open position based upon a detected presence of the unknown object; and
autonomously propelling the working machine through the gate opening under control of the machine controller.