Patent ID: 12204339

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Referring now in detail to the drawing figures, in which like reference numerals represent like elements throughout the several views,FIGS.1and2show a mobile autonomous agricultural system10comprising a powered mobile unit12. The mobile autonomous agricultural system10is configured to operate along rows40of crops (best shown inFIG.2, with each row40shown extending into the page) to perform agricultural tasks, such as harvesting, husbandry, or monitoring the crops.

In this example, the mobile unit12comprises an arch profile extending along an axial direction50. In other words, at any point in the axial direction, a cross section of the mobile unit12comprises an arch profile. In this example, distal ends of arms of the arch are fixed to powered wheels14(which are pivotable with respect to the mobile unit12for steering) and extend away from the wheels14to an apex of the arch. In this example, each distal end of the arch is attached to two wheels14, such that the whole arch is supported on the ground by a total of four wheels14. It will be appreciated that in other examples, any suitable number of wheels may be used, or any other suitable device for propelling the mobile unit12may be used.

The arch profile of the mobile unit12defines an inner zone16, in the form of a tunnel extending along the axial direction50, within which agricultural equipment22is disposed such that it is protected from damage. The agricultural equipment22in this example comprises robot arms. In other examples, it may include UV tubes or any other suitable equipment for carrying out agricultural tasks. The arch profile further allows the mobile unit12to traverse along rows40of crops, which are raised above the ground on posts (for ease of accessibility), with a single row40of crops extending through the inner zone16along the axial direction50, and simultaneously accessible by the agricultural equipment from two sides of the row40. In some examples, the crops may be disposed on the ground, and the mobile unit may comprise any suitable profile to access the crops on the ground.

The mobile autonomous agricultural system10comprises a controller20which is configured to control the travel of the mobile unit12. In this example, in an autonomous mode, the controller20is configured to autonomously move the mobile unit12along the rows40of crops, and between the rows40, where the rows may comprise a straight line of crops, or any other line of crops with a non-linear profile. In other words, the controller20is configured to align the axial direction50of the inner zone16of the mobile unit12with a first row40of crops such that the arch profile is centered and aligned with the row40of crops, and to move the mobile unit12to approach the first row40, and continue to move the mobile unit12along the row40, with the first row40received in the inner zone16until it reaches an end of the row40. At the end of the row40, the controller20is configured to control the mobile unit12to exit the row40, travel a predetermined distance away from the row40, and traverse towards an adjacent row40to begin the process again with the adjacent row40. In this example, the mobile autonomous agricultural system10may also be operated in a manual mode, in which a user can manually control the movement of the mobile unit12, for example up to a first row40, at which point the user may activate the autonomous mode.

In this example, the autonomous mode of the mobile autonomous agricultural system10provides for autonomous movement between adjacent rows40of crops, in a single polytunnel of plants, and also from one polytunnel to another.

During this autonomous movement, it is important that people around the mobile autonomous agricultural system10are kept safe. For example, during the approach of the mobile unit12towards a row40, there is a risk of crushing a person between the mobile unit12and the row40. Further, there are also risks during movement of the mobile unit12along the row40, and outside the row40which must be mitigated to ensure the safety of people around the mobile unit12.

To this end, the agricultural system10comprises a plurality of laser curtain sensors18distributed around the mobile unit12. In this example, there are six laser curtain sensors18, with one corner laser curtain sensor18adisposed at each of four corners of the mobile unit12, which in this example is by each wheel14, and one side laser curtain sensor18bdisposed on each side of the mobile unit12between two wheels14in the axial direction50.

The laser curtain sensors18are each configured to project a respective laser plane towards the ground, and each laser plane overlaps with at least one other laser plane, so as together to form a laser curtain surrounding the mobile unit12. Each laser curtain sensor18can detect when its respective laser plane is interrupted by sensing reflected waves of emitted laser beam light. Specifically, the two side laser curtain sensors18bproject a laser plane close to vertically downwards such that the respective laser planes are not interrupted by the wheels14if the wheels are rotated by 90 degrees, and so that the respective laser planes are not interrupted by adjacent rows40when the mobile unit12is moving along a row40. As is explained in more detail below, this helps to reduce the risk of erroneous generation of a safety output. When the distance between rows is larger, the side laser curtains may be angled away from the mobile unit, or when the distance between the rows is narrow and constraining, and the wheels are smaller or do not rotate, then the side laser curtains may be angled towards the mobile unit.

Each corner laser curtain sensor18ais configured to project a laser plane angled downwards with respect to the horizontal to project away from the mobile unit12, such that each laser plane from the corner laser curtain sensors18aoverlaps with the laser plane from an adjacent corner laser curtain sensor18a, and so that the laser plane from each side laser curtain sensor18boverlaps (or meets) with the laser planes from the adjacent corner laser curtain sensors18a.

This particular configuration of laser curtain sensors18ensures that the mobile unit12is wholly surrounded by the laser curtain such that the presence of an object such as a person can be detected anywhere around the mobile unit12. It will be appreciated that there may be any suitable number of laser sensors for the particular application of the mobile autonomous agricultural system, such as one laser curtain sensor, or more than one laser curtain sensor.

The mobile autonomous agricultural system10further comprises a location module24which is configured to monitor a location of the mobile unit12relative to a row40. The location module24may comprise GPS or any other suitable sensor which can be used to identify the location of the mobile unit relative to a row.

The mobile autonomous agricultural system10further comprises a safety module26which is configured to receive a location signal from the location module24, related to the location of the mobile unit12relative to a row40, and to select a mode of operation based on the received location signal. Each mode of operation comprises processing the laser curtain in a different predefined laser curtain pattern to monitor interruptions to the laser curtain within the laser curtain pattern, as explained below with reference toFIGS.3-7.

For each mode of operation, the safety module26is configured to generate a safety output in response to determining that the laser curtain is interrupted within the laser curtain pattern of the respective mode of operation. Therefore, any interruptions of the laser curtain outside the laser curtain pattern are ignored by the safety module.

In this example, the safety output includes sending a signal to the controller to control the mobile unit12to stop, and to control the robot arms22to stop. The safety output bringing the mobile unit to instant halt when the laser curtain pattern is interrupted, and the laser curtain patterns changing between modes, provides the compliance to regulation legislated for use of an autonomous system where there are likely to be people in the vicinity, while improving operation capability for the mobile unit not to be erroneously halted by anything not related to people straying too close to the mobile unit. Such solutions are currently unavailable for use in the agricultural environment where a crop is planted in rows. In some examples, the safety output signal may be to slow the mobile unit or to slow the robot arms. In other examples, the safety output may alternatively or additionally comprise producing an alarm, such as actuating an audible alarm on the mobile unit, or an alarm remote from the mobile unit to an operator, to alert the operator to the potential threat to safety of a person, or to alert the operator to the immobilising of the mobile unit or robot arms, such that they can restart the mobile unit or robot arms when it is determined to be safe again.

Although the location module, the safety module and the controller have been described as separate components, it will be appreciated that they can be incorporated into a single unit.

Further, although it has been described that the profile of the mobile unit defines an arch with distal ends of the arch fixed to wheels, in other examples, the mobile unit may have any suitable profile, or the arch profile may be inverted so that a portion of the arch at the apex is fixed to wheels and the distal ends extend upwards, away from the wheels and the ground. This can be used in situations where the crops are suspended from above, such that an inner zone between arms of the arch receives the suspended crop, and the crop is accessible to agricultural equipment in the arch from two sides simultaneously. For these examples, and the specific example described above, the axial direction may be the direction on the mobile unit which is configured to be parallel to a row while the controller controls the mobile unit to move along the row.

FIGS.3and4show the mobile autonomous agricultural system10with a laser curtain pattern100in a default mode. The default mode is selected by the safety module26unless any deviating criteria are met. For example, the default mode in this example is selected when the mobile unit12is outside the rows40of crops and is moving from a location at which it has been switched from the manual mode to the autonomous mode, and when the mobile unit12is moving from one polytunnel comprising rows40of crops to another polytunnel comprising rows40of crops. During these periods, no deviating criteria are met.

In this example, the laser curtain pattern100in the default mode extends from each of the wheels14, away from the mobile unit12, in the axial direction50up to a maximum axial distance30, which in this example is 2 m. The laser curtain pattern100in the default mode also extends from each of the wheels14, away from the mobile unit12, in a width direction60, which is perpendicular to the axial direction50, up to a maximum width distance32, which in this example is 2 m.

Therefore, when a person or other unexpected object strays within 2 m of the wheels14of the mobile unit12when in the default mode, the safety module26determines that the laser curtain is interrupted within the laser curtain pattern100for the default mode, and generates the safety output.

In other examples, the maximum axial distance and the maximum width distance may be any suitable distance, such as between 1-3 m.

FIG.5shows the mobile autonomous agricultural system10with a laser curtain pattern200in a crabbing mode. The crabbing mode is selected by the safety module26when a first deviating criterion is met. In this example, the first deviating criterion comprises the mobile unit12being controlled to move, outside the rows40of crops, from one row40to align with another row40.

In this example, the laser curtain pattern200in the crabbing mode extends from the wheels14of the mobile unit12, along the axial direction50up to a minimum axial distance36, and in the width direction60up to the maximum width distance32. In this example, the minimum axial distance36is 0.8 m, and the maximum width distance32is the same as for the default mode. Therefore, the laser curtain pattern200for the crabbing mode in this example is similar to the default mode except that the axial distance is shorter. This is because, in the crabbing mode, the mobile unit12would only be moving in the width direction60(as shown inFIG.1) such that this direction is more critical, and requires a larger distance for the laser curtain pattern200, whereas, there is no movement in the axial direction50(as shown inFIG.1) in the crabbing mode, such that the important safety feature is merely preventing entry to the inner zone16of the mobile unit12while it is operating. It will be appreciated that the axial and width extents may be different to suit other agricultural applications.

FIG.6shows the mobile autonomous agricultural system10with a laser curtain pattern300in an entry mode. The entry mode is selected by the safety module26when a second deviating criterion is met. In this example, the second deviating criterion comprising the mobile unit12being controlled to approach the rows40, from outside the rows40, and the signal from the location module24indicating that the mobile unit12is within a first threshold distance from an end of a row40. In this example, the first threshold distance is the same as the maximum axial distance30. In other examples, it will be appreciated that the threshold distance may be any suitable distance.

In this example, the laser curtain pattern300in the entry mode extends from the wheels14of the mobile unit12, along the axial direction50up to the maximum axial distance30, and in the width direction60up to the maximum width distance32(i.e., with a similar pattern to the default mode). The laser curtain pattern300in the entry mode differs from that in the default mode by the laser curtain pattern300excluding at least one channel38from processing by the safety module26, which channel38corresponds to the position of the row40. This channel38ensures that the safety output from the safety module26is not erroneously generated by the posts and crops in the rows40, while maintaining the laser curtain pattern300to surround the rest of the mobile unit12, particularly between the mobile unit12and the rows40, where there remains a risk of crushing a person therebetween. The channel38may be configured to grow dynamically based on the location of the mobile unit12relative to the row40. For example, as the mobile unit12is entering a row40, the channel is configured to grow to accommodate the row40while ensuring that the rest of the space between the end of the row40and the mobile unit12remains covered by the laser curtain pattern.

In other examples, the laser curtain pattern for the entry mode may be similar to the crabbing mode, and the first threshold distance may be the same as the minimum axial distance. Alternatively, the laser curtain pattern may have any suitable extents, while excluding at least one channel corresponding to the row. For example, the entry mode may be similar to the default mode excluding the channel when the deviating criterion is met directly after the default mode has been active, and the entry mode may be similar to the crabbing mode excluding the channel when the deviating criterion is met directly after the crabbing mode has been active.

FIG.7shows the mobile autonomous agricultural system10with a laser curtain pattern400in a row mode. The row mode is selected by the safety module26when a third deviating criterion is met, the third deviating criterion comprising the mobile unit12being within a second threshold distance from an end of a row40or within the row40(i.e., with a row40received within the inner zone16of the mobile unit12).

In this example, the laser curtain pattern400in the row mode extends from the wheels14of the mobile unit12, along the axial direction50up to the maximum axial distance30, and in the width direction60up to a minimum width distance42. In this example, the minimum width distance42takes the laser curtain pattern400up to the side laser curtain sensor18b.

The row mode therefore ensures that the safety output from the safety module26is not erroneously generated by the posts and crops in the rows40, while maintaining the laser curtain pattern300to surround the rest of the mobile unit12, in any direction in which a person could approach the mobile unit12.

Although only four modes have been described, there may be any number of different modes which take account of different configurations of rows, and of movements that the controller is configured to control the mobile unit to make. For example, the rows may be non-linear, and the modes may be configured to take account of this, and to dynamically change based on the configuration of the rows. Further, the laser curtain patterns may be dependent on the specific shape of the mobile carrier, which may have different angles of approach for a person, and therefore different potential vulnerabilities in use.

Having the laser curtain processed in different modes of operation with different laser curtain patterns, dependent on the location of the mobile unit relative to rows of crops, makes the mobile autonomous agricultural system very versatile in use while maintaining the safety of people around it.

In this example, for each of the modes of operation, the laser curtain pattern also extends downwards from each of the laser curtain sensors18towards the ground (best shown inFIG.4) up to a threshold ground distance34from the ground. In this example, the threshold ground distance34is 20 cm. Limiting the laser curtain pattern for each mode of operation up to the threshold ground distance34means that the mobile autonomous agricultural system10can be used on uneven ground, as the safety module26will not erroneously detect an interruption in the laser curtain pattern due to an uneven surface, while still triggering a safety output for a person who may attempt to crawl under, or may be lying prone on the ground. In some examples, the threshold ground distance may be any distance between 10 cm and 50 cm. In other examples, there may be no threshold ground distance, such that the laser curtain pattern extends all the way to the ground.

Further, for each of the modes of operation, the laser curtain sensors18are also configured to monitor and map the ground surface, which may be uneven, undulating, or inclined. The laser curtain pattern for each mode of operation may be dynamically altered based on the mapped ground surface, for example, if it is determined that the inclination of the ground is above an inclination threshold, the laser curtain pattern may be dynamically altered to make the axial distance or the width distance for the respective mode of operation shorter.

Although the laser curtain sensors are described as projecting a laser plane, it will be appreciated that the laser plane may be a single linear laser which is moved rapidly back and forth through a plane or about a pivot axis to form an effective laser plane. Further, although it is described that there are six laser curtain sensors, there may be any suitable number of laser curtain sensors, such as a single laser curtain sensor or more than one laser curtain sensor which are configured to project a laser curtain away from the mobile unit.

Further, although the laser curtain patterns are described in specific examples above, it will be appreciated that any suitable laser curtain pattern may be used for each of the different modes of operation, and the laser curtain sensors can be angled at any suitable angle to ensure that the safety output is not erroneously generated.

FIG.8is a flow chart showing steps of a method500of controlling the powered mobile unit12of the mobile autonomous agricultural system10.

In block502, the method500comprises projecting the laser curtain away from the mobile unit12with the laser curtain sensors18to surround the mobile unit12. In other examples, the laser curtain may not surround the mobile unit, but may be placed, for example, in strategic positions.

In block504, the method500comprises determining the location of the mobile unit12relative to a row40, based on the signal from the location module24. For example, the safety module26may determine the mobile unit12to be in one of the following five locations, based on the location signal received from the location module24and optionally also a signal from the controller20:outside the rows40,approaching an end of a row40from outside the row40, within a first threshold distance of an end of the row40,approaching an end of a row40from outside the row40, within a second threshold distance of an end of the row40;within the row40; ormoving between rows40outside the rows40.

In this example, in block506, the method500comprises determining whether any deviating criteria are met. The deviating criteria may include, for example, any of the first deviating criterion, the second deviating criterion and/or the third deviating criterion described with reference toFIGS.5-7. It will be appreciated that other deviating criteria may be applied.

If it is determined that there are no deviating criteria met, the method500proceeds to block508, in which the default mode is selected, for example, as described with reference toFIGS.3and4.

If it is determined in block506that any deviating criteria have been met, the method proceeds to block510in which a mode other than the default mode is selected. For example, depending on the deviating criterion which is met, the method500may select a crabbing mode as described with reference toFIG.5, an entry mode as described with reference toFIG.6, or a row mode as described with reference toFIG.7. As described above, each mode of operation comprises a different laser curtain pattern which is configured to be processed.

In other examples, blocks506-510may comprise any suitable method for selecting different modes of operation based on the location of the mobile unit relative to a row.

From both blocks508and510the method500proceeds to block512, in which it is determined whether the laser curtain has been interrupted within the respective laser curtain pattern for the selected mode of operation.

If the laser curtain has been interrupted within the selected laser curtain pattern, the method proceeds to block514which comprises generating a safety output such as sending a signal to control the mobile unit12to stop, or to control the robot arms to stop, or any other suitable safety output such as described above.

If the laser curtain has not been interrupted within the selected laser curtain pattern, then the method500returns back to block502to start again. This method500is carried out continually to ensure the safety of users around the mobile unit12.

It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

It is to be understood that this invention is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only. Thus, the terminology is intended to be broadly construed and is not intended to be limiting of the claimed invention. For example, as used in the specification including the appended claims, the singular forms “a,” “an,” and “one” include the plural, the term “or” means “and/or,” and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. In addition, any methods described herein are not intended to be limited to the sequence of steps described but can be carried out in other sequences, unless expressly stated otherwise herein.

While the invention has been shown and described in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention as defined by the following claims.