FIELD OF INVENTION

[0001] The present invention relates to a method of detecting uneven or undulating ground or ground protrusions for use with autonomous deposition machines (ADM) to improve print accuracy, print speed, granularity, and scalability, for a large-scale ground printing application. Specifically, but not exclusively, an ADM of a type equipped to deposit materials such as ink and paint, but which may equally deposit sand, seed, fertiliser, or other ground treatments onto a ground surface, or for injection under pressure into a ground surface. Each ADM may be completely autonomous (i.e. free from human operation and/or supervision) or may require at least partial human operation and/or supervision, depending on the application.

BACKGROUND

[0002] Uneven ground is an issue in many sectors for example, in agricultural applications, self-propelled harvesters, such as autonomous combine harvesters, usually include a header for engaging a number of transversely spaced rows or a substantial width of crop. To maintain the header at the desired level above the ground or below the crop heads for efficient harvesting and for header grounding avoidance, an automatic header height control system is provided which typically includes a mechanical feeler or an acoustic sensor or similar non-contact ground sensing device mounted on the header. Examples of previously available devices are shown in US4,776,153, which shows a header height control system with a plurality of feelers and tilt control.

[0003] Another sector where uneven or ground undulations cause issues is ground marking. Ground marking is typically carried out manually, however, for applications wherein the ground marking is carried out autonomously; it requires significant pre-planning, creating print instructions for the robot to carry out, and the like. Where marking is required such as for logos, safety or hazard signs, the complex make-up of these images means that difficulties persist to print any image, any size, any colour, directly onto any ground surface without significant cost of time, expense and compromise in image attributes such as resolution. Adding in, on-site variability in ground unevenness or undulations causes issues that require significant resources to correct (both computationally, and manpower), which in extreme cases can give the impression manual ground marking would have been more favourable for a specific site. [0004] Although available control systems generally provide good position control in most situations and relieve the operator of the tedious job of manually adjusting height or tilt with changing ground conditions, several problems exist with these systems. Hydraulic power requirements and material stress levels often are high when the lift systems are providing a fast response. The systems often fail to respond in time to avoid inefficiencies, excessive material deposition or inaccuracies, or grounding and damage of the deposition header. System response time is a problem when the autonomous deposition robot is travelling at relatively high speeds, such as when operating in field conditions wherein crop yield is low, and when the autonomous deposition robot is operating in fields having substantial ground contour changes. Tilt response time at high speeds or in fields with very uneven surface contours is often too slow for headers having automatic tilting systems to maintain the header generally parallel to the ground such as shown in the aforementioned U.S. Pat. No. 4,776,153. Header grounding and damage, and improper header operating height, result in decreased productivity. When the autonomous robot is crossing depressions such as valleys, gullies or swales, the header can be grounded and damaged before the deposition header can respond to the sudden rise in the ground surface. Grounding is a particular problem when the driving wheels are in a depression and the deposition header is in a raised surface area. Near the apex of a hill or mounded area, the deposition header is often too high and accuracy is low since the system cannot respond quickly to the abrupt change in ground surface.

SUMMARY OF INVENTION

[0005] It is therefore an object of the present invention to provide improved resolution, accuracy, and grounding avoidance on an uneven surface. It is a further object to provide such a control system which overcomes most or all of the aforementioned problems.

[0006] According to a first aspect of the invention, there is provided a computer-implemented method of determining a deposition head height parameter for an autonomous deposition robot on an uneven ground surface, the method comprising: driving the autonomous deposition robot in a first direction; receiving a first profile of the ground surface in a second direction, perpendicular to the first direction; and determining the deposition head height parameter for a deposition head, wherein the deposition head height parameter is based on the profile of the ground surface.

[0007] In some examples, the method further comprises scanning the deposition head in the second direction above the ground surface. In some examples, the profile of the ground surface is first detected by a plurality of sensors while the deposition head is scanned in the second direction.

[0008] In some examples, detecting a profile of the ground surface further comprises operating a sensor to detect a first portion of the ground surface; calculating a first plurality of distance values from the deposition head to the first portion of the ground surface; and storing the first plurality of distance values from the deposition head to the first portion of the ground surface as discrete elements in a first array, wherein the first array is a 2d array in the second direction. [0009] In some examples, the method further comprises driving the autonomous deposition robot in the first direction one step; operating the sensor to detect a second portion of the ground surface; calculating a second plurality of distance values from the deposition head to the second portion of the ground surface; and storing the second plurality of distance values from the deposition head to the second portion of the ground surface as discrete elements in a second array; wherein the second array is a 2d array in the second direction and the first portion of the ground surface abuts the second portion of the ground surface. In some examples, one step is equal to the size of an area of deposition of the deposition head.

[0010] In some examples, the method, further comprises depositing material on the ground surface using the head height parameter as the height of the deposition head. In some examples, the material for deposition is at least one of a herbicide, pesticide, insecticide, plant growth aid, water, or marking material. In some examples, the deposition on the ground surface is carried out in a plane corresponding to the first profile. In some examples, the detection of the profile of the ground surface and the deposition of material on the ground surface are carried out in parallel.

[0011] In some examples, the method further comprises sending the deposition head height parameter to at least one other autonomous deposition robot. In some examples, the first profile of the ground surface abuts the second profile of the ground surface. In some examples, a third profile is received, the third profile being user-originated via a cloud server or device, or an edge server or device.

[0012] According to a second aspect of the invention, there is provided a system for determining deposition instructions for an autonomous deposition robot on an uneven ground surface, wherein the autonomous deposition robot is operable to deposit material on the uneven ground surface, the system comprising: a first autonomous deposition robot, wherein each autonomous deposition robot comprises: at least one receptacle to hold a deposition material; at least one deposition arrangement; a locomotion arrangement; and a control unit, the control unit configured to: instruct the locomotion arrangement to drive the autonomous deposition robot in a first direction; receive a first profile of the ground surface in a second direction, perpendicular to the first direction; and determine a deposition arrangement height parameter, wherein the deposition height parameter is based on the profile of the ground surface.

[0013] In some examples, the system comprises a sensor arrangement, the sensor arrangement comprising at least one of a LiDAR sensor, an LED time of flight sensor, a camera, an ultrasonic sensor, or a light source.

[0014] In some examples, the control unit is further configured to operate the sensor arrangement to detect a first portion of the ground surface; calculate a first plurality of distance values from the deposition arrangement to the first portion of the ground surface; and store the first plurality of distance values from the deposition arrangement to the first portion of the ground surface as discrete elements in a first array, wherein the first array is a 2d array in the second direction.

[0015] In some examples, the control unit is further configured to instruct the locomotion arrangement to advance in the first direction one step, a step being equivalent to a deposition area of the deposition arrangement; operate the sensor arrangement to detect a second portion of the ground surface; calculate a second plurality of distance values from the deposition arrangement to the second portion of the ground surface; and store the second plurality of distance values from the deposition arrangement to the second portion of the ground surface as discrete elements in a second array; wherein the second array is a 2d array in the second direction and the first portion of the ground surface abuts the second portion of the ground surface.

[0016] In some examples, the locomotion arrangement is a ground wheel arrangement.

[0017] In some examples, the autonomous deposition robot further comprises a chassis with a traverse guide, the deposition arrangement affixed to the traverse guide in operation, the traverse guide permitting movement of the nozzle array in the second direction beyond the width of the ground wheel arrangement.

[0018] In some examples, the traverse guide is movable relative to the ground wheel arrangement in the second direction, so that material can be deposited an area while the ground wheel arrangement is stationary.

[0019] In some examples, the material for deposition is at least one of a herbicide, pesticide, insecticide, plant growth aid, water, or marking material. [0020] According to a third aspect of the present invention, there is provided a computer- implemented method of determining deposition instructions for an autonomous deposition robot on an uneven ground surface, the method comprising: driving the autonomous deposition robot in a first direction; detecting a first profile of the ground surface in a second direction, perpendicular to the first direction; and determining deposition instructions for the autonomous deposition robot, the deposition instructions comprising a deposition head height parameter, wherein the deposition head height parameter is based on the profile of the ground surface.

[0021] In some examples, the method further comprises scanning the deposition head in the second direction. In some examples, the profile of the ground surface is detected while the deposition head is scanned in the second direction.

[0022] In some examples, the method further comprises depositing material on the ground surface according to the deposition instructions. In some examples, the deposition on the ground surface is carried out in a plane corresponding to the first profile.

[0023] In some examples, further comprising detecting a second profile of the ground surface, parallel to and abutting the first profile. In some examples, the second profile of the ground surface and the deposition of material on the ground surface are carried out in parallel.

[0024] In some examples, the deposition instructions comprise a plurality of substantially equal-sized cells located over the ground surface, each cell having a deposition head height parameter. In some examples, wherein each row of the substantially equal-sized cells are parallel to the second direction, and each column is parallel to the first direction. In some examples, the method further comprises advancing the driving of the autonomous deposition robot in the first direction in steps equal to the size of the substantially equal-sized cells in the deposition instructions.

[0025] In some examples, the method further comprises sending the deposition instructions to at least one other autonomous deposition robot.

[0026] In some examples, the depositions instructions are user-originated via a cloud server or device, or an edge server or device.

[0027] In some examples, the detecting a profile of the ground surface comprises: irradiating the ground surface with light from a light source; detecting a luminance reflected from the ground surface irradiated with light from the first light source; calculating a distance from the light source to the ground surface based on the detected luminance; and amending the deposition head height parameter of the deposition instructions based on the calculated distance. [0028] According to a fourth aspect of the present invention, there is provided system for determining deposition instructions for a plurality of autonomous deposition robots on an uneven ground surface, wherein each of the multiple autonomous deposition robots are operable to deposit material on the uneven ground surface. The system comprising a first autonomous deposition robot, and a second autonomous deposition robot, wherein each autonomous deposition robot comprises: at least one receptacle to hold a deposition material; at least one deposition arrangement; a locomotion arrangement; a sensor arrangement; a control unit, the control unit configured to: instruct the locomotion arrangement to drive the autonomous deposition robot in a first direction; instruct the sensor arrangement to detect a first profile of the ground surface in a second direction, perpendicular to the first direction; and determine deposition instructions for the autonomous deposition robots, the deposition instructions comprising a deposition arrangement height parameter, wherein the deposition height parameter is based on the profile of the ground surface.

[0029] In some examples, the sensor system comprises a computer vision system. In some examples, the computer vision system comprises a camera.

[0030] In some examples, the locomotion arrangement is a ground wheel arrangement.

[0031] In some examples, the system further comprises a chassis with a nozzle array on a traverse guide, the traverse guide permitting movement of the nozzle array in the second direction beyond the width of the ground wheel arrangement. In some examples, the traverse guide is fixed in relation to the ground wheel arrangement. In some examples, the traverse guide is movable relative to the ground wheel arrangement in the second direction, so that material can be deposited an area while the ground wheel arrangement is stationary.

[0032] In some examples, the material for deposition is a herbicide, pesticide, insecticide, plant growth aid, water or marking material; and optionally, wherein the marking material is paint, ink, coloured material, or powder.

[0033] In some examples, the sensor arrangement comprises a light source, the control unit further configured to: instruct the sensor arrangement to irradiate the ground surface with light from the light source; detect a luminance reflected from the ground surface irradiated with light from the first light source; calculate a distance from the light source to the ground surface; and amend the deposition head height parameter based on the calculated distance.

[0034] Thus, there is provided an improved high-resolution grand-scale accuracy of ground printing and deposition systems. Furthermore, delivering world-leading navigational accuracy for a ground marking system ensures market-leading flexibility, scalability, ease-of-use, and robustness for the ground marking systems. With these elements in place, ADMs such as the one disclosed in this application are able to fully satisfy even the most extreme scale market demands such as ‘full pitch’ print activations used in the NFL (National Football League). There is also provided a ground marking autonomous robot that in addition to high accuracy and throughput marking provides a way of accounting for an uneven ground surface when depositing a material.

LIST OF FIGURES

[0035] Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0036] FIG. 1 is a side view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein;

[0037] FIG. 2 is a plan view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein;

[0038] FIG. 3 is a flow diagram of a process for determining deposition instructions for an autonomous deposition robot on an uneven ground surface, in accordance with at least one of the examples described herein;

[0039] FIG. 4 illustrates a graphical user interface for ground profile input, in accordance with at least one of the examples described herein;

[0040] FIG. 5 is a flow diagram of a process for creating a ground profile, in accordance with at least one of the examples described herein;

[0041] FIG. 6 is a front cutaway view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein;

[0042] FIG. 7 is a front view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein;

[0043] FIG. 8 is a diagrammatic view of an embodiment of ground deposition apparatus, in accordance with at least one of the examples described herein;

[0044] FIG. 9 is a schematic diagram of an exemplary apparatus for ground deposition, in accordance with at least one of the examples described herein; and

[0045] FIG. 10 illustrates a block diagram of a computing module, in accordance with at least one of the examples described herein.

[0046] The present techniques will be described more fully hereinafter with reference to the accompanying drawings. Like numbers refer to like elements throughout. Parts of the autonomous ground deposition robot are not necessarily to scale and may just be representative of components of the ground print machines, or other described entities.

DETAILED DESCRIPTION

[0047] FIG. 1 is a side view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein. FIG. 1 shows an autonomous deposition robot 10 comprising a case 12 held securely by a chassis (not shown) supporting the ground wheel arrangement 24 with a deposition head 60 on a traverse guide 62 comprising a nozzle array (see FIG. 2, described below).

[0048] FIG. 2 is a plan view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein. As shown in FIG. 2, the ground wheel arrangement 24 (also referred to as a locomotion arrangement) further comprises wheels 24a, 24b, 24c and 24d to steer the autonomous deposition robot 10 along a path to affect the deposition of material, and this may be under the control of a file comprising instructions that can be loaded into the onboard control system such as may be contained in the system controller 22 comprising a communications module, which may be updated over a server connection or via the cloud (not shown).

[0049] In the present example, it will be appreciated that the cloud may comprise any suitable data processing device or embedded system which can be accessed from another platform such as a remote computer, content aggregator or cloud platform which receives data posted by the autonomous deposition robot 10. As referred to herein, processing circuitry should be understood to mean circuitry based on one or more microprocessors, microcontrollers, digital signal processors, programmable logic devices, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), etc., and may include a multi-core processor (e.g., dual-core, quad-core, hexa-core, or any suitable number of cores) or supercomputer. In some examples, processing circuitry may be distributed across multiple separate processors or processing units, for example, multiple of the same type of processing units (e.g. two Intel Core i7 processors) or multiple different processors (e.g., an Intel Core i5 processor and an Intel Core i7 processor); as described in more detail with reference to FIG. 10 below. In some examples, or the system controller 22 or cloud executes instructions for each autonomous deposition robot 10.

[0050] In operation, nozzle array 42 can deposit materials from material reservoirs (see FIG. 6). The nozzle array 42 may be attached to the deposition head 60. The reservoirs may contain different colours of marking materials. The reservoirs may comprise any material for deposition, for example, a marking material or a chemical to deposit on the ground, such as a herbicide, pesticide, insecticide, paint, ink, coloured material, powder, fertilizer, plant growth aid or water, (in powder, concentrate, or resin form). Provided that compatible hoses and nozzle arrays (i.e., in place of, or in addition to, nozzle array 42) are attached, the autonomous deposition machine is considered capable of functioning on any ground surface that may comprise uneven ground.

[0051] The traverse guide 62 permits movement of the print head 60 beyond the width W of the ground wheel arrangement 24, along the length of the standard operation width 68 (sometimes collectively referred to as a deposition arrangement). The nozzles of the nozzle array 42 may be fixed and the print head 60 is moveable in a vertical direction (i.e., the z- direction or the same direction as gravity acts). The deposition head 60, via the traverse guide 62, is also moveable along the length of the operation width 68, which is the area the deposition head is capable of printing in ‘normal’ operation. The vertical position of the deposition head is configurable via input of a deposition head height parameter within the deposition instruction provided to the autonomous deposition robot. In particular, the deposition head height parameter is based on the profile of the ground surface, this is be covered in more detail below. [0052] In the case of inks or paints, the deposition materials may comprise CYM or, if good black is required, CYMK colours. When depositing ink or paint to print an image, the image may be printed in sweeps to generate small adjacent dots (i.e. each dot comes from a single nozzle of the nozzle array 42), and when viewed from above or a suitable distance from afar (e.g. from the stand in a stadium or from a television view) appear to blend into colours, depending on the relative colours of the different inks or colours deposited.

[0053] In the case of agricultural deposition materials such as herbicides, pesticides, insecticides, fertilizer, or plant growth aid, the deposition materials may comprise concentrates in powder, liquid, or resin form. When depositing agricultural deposition materials to an uneven ground surface, the autonomous deposition machine may mix the concentrates with water, or some other solvent, before being deposited.

[0054] In some examples, the autonomous ground marking robot 10 further comprises a fisheye camera, with a field of view (not shown) aligning with the first printing nozzle of the nozzle array 42. The camera may be a part of a computer vision system that is used to monitor the ground height and adjust the height of the deposition head accordingly, allowing for more accurate image printing or material deposition. The camera may also be used for tracking the progress of the deposition, or print if a technique, such as tiling, is required to print an image larger than the width of the autonomous ground marking robot 10. Other suitable sensor technologies may also be used.

[0055] The ground wheel arrangement 24 comprises wheels 24a, 24b, 24c and 24d to steer the autonomous ground marking robot 10 along a path to affect the printing, and this may be under the control of a print file that can be loaded into an on-board control system, such as may be contained in a smart communications module 22. The traverse guide 62 is fixed in relation to the ground wheel arrangement 24, so that it prints one line of an image along the print width 68. The ground wheel arrangement 24 then advances, moving the whole autonomous ground marking robot 10 forward for it to then print another line.

[0056] FIG. 3 is a flow diagram of a process for determining deposition instructions for an autonomous deposition robot on an uneven ground surface, in accordance with at least one of the examples described herein. Process 300 may start at step 310. At step 310, an autonomous deposition robot is driven in a first direction. At step 320, a first profile of a ground surface in a second direction is received, the second direction being perpendicular to the first direction. For example, the autonomous deposition robot may be driven in a direction the robot is facing (referred to herein as forwards), and the profile of the ground surface, directly in front of the robot may be detected perpendicular to the direction the robot is travelling (referred to herein as width ways).

[0057] In more detail, the second direction is the direction that the deposition head 60 travels on traverse guide 62. As the second direction is the direction that the deposition head travels when depositing material on the ground, it is this direction that potential grounding of the deposition head may occur and is to be avoided - this is different to common solutions found, particularly in the agricultural industry, which has a fixed boom/harvesting device that travels in the same direction as the combine harvester and is concern with grounding incidents in that same direction.

[0058] At step 330, a deposition head height parameter is determined for a print head of the autonomous deposition robot. The deposition instructions comprise a deposition head height parameter, wherein the deposition head height parameter is based on the detected profile of the ground surface. The detection mechanisms for the ground profile may comprise ultrasound, infrared, and parallax imaging and accompanying methodologies known in the art. However, process 300 may further comprise scanning the deposition head in the second direction above the ground surface, and the profile of the ground surface is detected while the deposition head is scanned in the second direction with a plurality of sensors configured to detect unevenness in a ground surface.

[0059] Alternatively, a plurality of sensors may be located along the operational width 68 of the autonomous deposition robot such that the unevenness is passively detected as the autonomous deposition robot moves in the first direction. In such a configuration, the sensors are ideally located ahead of the deposition arrangement.

[0060] The process 300 may further comprise depositing material on the ground surface according to the deposition instructions. In some examples, the deposition on the ground surface is carried out in a plane corresponding to the first profile (i.e., in the second direction), and, while depositing material on the ground surface according to the first profile, simultaneously, or in parallel to, detecting a second profile of the ground surface, parallel to and abutting the first profile. This can be achieved with a plurality of sensors located along the operational width 68 of the autonomous deposition robot or with a plurality of sensors located on the deposition arrangement (or the deposition head 60 in particular) aimed an area abutting, ahead, and parallel to the area of deposition of nozzle array 42.

[0061] FIG. 4 illustrates a graphical user interface for ground profile input, in accordance with at least one of the examples described herein. The sweep profile generator of FIG. 4 is a graphical user interface 400 to enable the user to manually input, or manually amend, a ground profile for an uneven ground surface in preparation for the accurate deposition of material to the ground surface. The user can tap input points 401 and record their position with button 411. After the first input is recorded, profile 402 is generated for display. The user can make fine adjustments to profile 402 with the fine adjustment inputs 412. If the user does not like the generated profile or the adjustments they have made, they can clear the profile with button 404. A base profile 402 may be generated by sensors or the like on the autonomous deposition robot as discussed herein.

[0062] Graph 420 shown in FIG. 4 comprises two axes, an x-axis 422 and a y-axis 424. The x- axis 422 is the displacement of the deposition head 60 on the traverse guide 62 from starting point on the farthest side to another. In the example shown in FIG. 4, the displacement is shown in mm, but any other suitable measuring system or unit is considered within the scope of this disclosure. The y-axis 424 is an indication of deposition head height from a maximum extension (a virtual bottom) of 0mm up to its most retracted position at, in this example, 95mm from full extension, either the x-axis 422 or the y-axis 424 can be normalized or configured to display such data in any reasonable manner, for example, the y-axis could show 0mm in the fully retracted position and 95mm in the fully extended position. If the user likes the generated profile, with the fine adjustments or the like they have made, they can send the profile with button 410 to the one or more autonomous deposition robots.

[0063] In operation, the autonomous deposition robot with advance forward in steps, and the deposition arrangement will traverse in an orthogonal direction to the direction of travel back and forth. At each pass, the deposition head will adjust to the head height parameter (the y-axis 424 value) at every position on the traverse guide (the x-axis 422) and thus follow the profile 402 of FIG. 4, and the uneven ground.

[0064] FIG. 5 is a flow diagram of a process for creating a ground profile, in accordance with at least one of the examples described herein. Process 500 or steps therein, may be carried out in parallel to, or subsequently to, process 300 or steps therein. Process 500 starts at step 505. Process 500 provides a user with a way of manually inputting and storing a ground profile. Process 500 may be used in conjunction with the graphical user interface 400 of FIG. 4.

[0065] At step 505, it is determined if a previous profile exists or not. If the answer to step 505 is no, process 500 continues on to step 510. If the answer to step 505 is yes, process 500 continues on to step 515. At step 515 it is determined if the previous profile needs updating. If the answer to step 515 is no, process 500 continues on to step 560. If the answer to step 515 is yes, process 500 continues on to step 510.

[0066] At step 510, a first user input of a new ground profile is received. The first user input may be a rough input on a device, such as a smartphone or a tablet, using an interface, such as graphical user interface 400. At step 525, it is determined if the ground profile is as desired. For example, a confirmation button can be displayed, or the like, which confirms whether or not the user would like to finely adjust the input. Accordingly, if the answer to step 525 is no, process 500 continues on to step 530. If the answer to step 525 is yes, process 500 continues on to step 550.

[0067] At step 530, it is determined if finer adjustment to the first user input of the new ground profile is required. For example, a confirmation button can be displayed, or the like, which confirms whether or not the user has completed it. Accordingly, if the answer to step 530 is no, process 500 optionally continues on to step 535 or returns to step 510. If the answer to step 535 is yes, process 500 continues on to step 540. At step 535, the new ground profile is cleared from cache storage, to allow the user to start over and create the new ground profile again. At step 540, a second user input of the new ground profile is received. The second user input is a more granular input than the first input. For example, the user may tap relative points on the graphical user interface 400 shown in FIG. 4, but then use the fine adjust buttons to input a more accurate position. After step 540, process 500 returns to step 525.

[0068] At step 550, the new ground profile is saved to a computer-readable medium, such as storage 1012, as described with reference to FIG. 10. At step 560, the profile is sent to the autonomous deposition robot to create or amend the deposition instruction for the autonomous deposition robot. For areas where the deposition is to be made at speed, for example, by agricultural machines depositing material to a large area; the deposition instructions are distorted, appropriately. By way of further explanation, this is similar to a process known as an anamorphosis in art and, for example, road signs. Anamorphosis is a distorted projection requiring the viewer to occupy a specific vantage point, use special devices, or both to view a recognizable image. An anamorphic algorithm can be used to convert the deposition instructions (for a marking on the ground or otherwise) to the desired viewing angle or to take into account an uneven surface. In some examples, the method further comprises receiving an image to be printed, receiving an expected viewing angle of the deposited paint, and applying an anamorphic algorithm to distort the marking to be printed. The technique of anamorphic projection can be seen quite commonly on text written at a very flat angle on roadways, such as "Bus Lane" or "Children Crossing", to make it easily read by drivers who otherwise would have difficulty reading obliquely as the vehicle approaches the text; when the vehicle is nearly above the text, its true elongated shape can be seen. Similarly, in many sporting stadiums, it is used to promote company brands, which are painted onto the playing surface; from the television camera angle, the writing appears as signs standing vertically within the field of play. [0033] FIG. 6 is a front view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein. As shown, the autonomous ground printer 10, comprises an outer case 12 cut away to reveal an array of primary packaging 14, 16, 18 and 20. The primary packaging 14, 16, 18 and 20 comprises deposition material, such as ink, paint, agricultural material, or the like held within a bag/container. Each primary packaging 14, 16, 18 and 20 is supported on a weight measuring plate 14a-d connected to an onboard control system 22. The onboard control system 22 further comprises a transceiver 22A for communication with remote resources, such as the cloud, for example over a wireless communication link.

[0034] Each weight measuring plate is an integral part of a frame 14a, 16a, 18a and 20a capable of holding the primary packaging 14, 16, 18, and 20 firmly in place and comprises a load sensor arrangement 28for registering the presence of the primary packaging 14, 16, 18, 20 when firmly in place in their respective frames. The primary packaging 14, 16, 18, 20 comprises an airtight valve outlet 34 sealed to bag 30 with the appropriate connection part for secure connection to a hose. The hose may also be a tube, piping, or any suitable means to transport the material for deposition. The autonomous deposition robot 10 further comprises wheels 24 for movement, a position sensor 38 and a laser 40. Position sensor 38 may comprise a Global Positioning Device for navigation or the autonomous printer 10 may use triangulation with known positioning reflectors and the laser 40 for positioning. Other navigational methods are described in the Applicant’s co-pending applications.

[0034] FIG. 7 is a plan view of a schematic diagram of an autonomous deposition robot, in accordance with at least one of the examples described herein. In the embodiment shown in FIG. 7, there is shown two autonomous deposition robots, working as a part of a system 700, each shown with an optional extra wide detachable deposition head accessory 100, which comprises an extra wide traverse guide 103, a second deposition head arrangement 102 and an extra nozzle array 101, in accordance with an embodiment of the present invention. The extra wide traverse guide 103 permits movement of the second deposition head arrangement 102 along the length of an extra wide print width 104. Wherein the detachable deposition head accessory 100 is connected, or coupled, to the chassis of the autonomous deposition robot 10 by a magnetic coupling 105a. The magnetic coupling 105a being powerful enough and strong enough to keep the detachable deposition head accessory 100 attached securely enough to minimise any lateral or vibrational movement between the detachable deposition head accessory 100 and the autonomous deposition robot 10 takes the form of an angled metal bracket surrounding a metal contact point, which completes an electrical connection between autonomous deposition robot 10 and detachable deposition head accessory 100. The magnetic connection 105a may be any suitable form of an angled metal bracket surrounding a metal contact point, which completes a tight coupling between the autonomous machine and the deposition accessory. In a similar way, the magnetic connection 105a may also comprise electrical contacts for passing data and/or power.

[0071] Also connecting the detachable deposition head accessory 100 to the autonomous deposition robot 10 is an umbilical 105b, wherein the umbilical 105b further comprises a serial data cable, a 10-amp power cable and 6 hydraulic lines (not shown). The umbilical 105b is connected to the autonomous deposition robot 10 via a male/female socket which is mounted on a mounting plate on the underside of the autonomous deposition robot 10 (not shown). Although any suitable connection means can be used for the specific parent/child arrangement needed. The serial data cable is connected to a sub-controller 22b, which further comprises an application processor (not shown), which comprises software code about the detachable deposition head accessory 100. The software code comprises key usage variables and information about the detachable deposition head accessory 100, which when the umbilical 105b is connected, the information is uploaded to the autonomous deposition robot 10 such that the autonomous deposition robot 10 can operate the detachable deposition head accessory 100. Thus, the detachable deposition head accessory 100 has independent processing capability and can carry out tasks that the ‘parent’ autonomous deposition robot 10 gives it.

[0072] As mentioned, the umbilical 105b also comprises hydraulic lines (not shown), which are connected to a reciprocal connector (not shown) on the underside of the autonomous deposition robot 10. When these hydraulic lines are connected and the detachable deposition head accessory 100 software is uploaded as previously mentioned, then the operation of the internal deposition head 62 is overridden and the internal deposition head 62 is now out of operation. As such, the autonomous deposition robot 10 can control the detachable deposition head accessory 100 and specifically, paints or deposition materials can be directly pumped to the nozzles in the extra nozzle array 101 of the deposition head 102 of the detachable deposition head accessory 100 via the serial data connection (not shown), the autonomous deposition robot 10 may also gather performance diagnostics of the detachable deposition head accessory 100, such as faults, error messages and or consumption of materials.

[0069] System 700 may be used for determining deposition instructions for a plurality of autonomous deposition robots on an uneven ground surface, wherein each of the multiple autonomous deposition robots are operable to deposit material on the uneven ground surface. System 700 comprises a first autonomous deposition robot 710, and a second autonomous deposition robot 720, wherein each autonomous deposition robot comprises: at least one receptacle to hold a deposition material, such as the deposition bag 30; at least one deposition arrangement 60; a locomotion arrangement, such as wheels 24a-d; a sensor arrangement, such as the GPS or camera technology discussed herein; and a control unit 22, the control unit configured to: instruct the locomotion arrangement to drive the autonomous deposition robot in a first direction; instruct the sensor arrangement to detect a first profile of the ground surface in a second direction, perpendicular to the first direction; and determine deposition instructions for the autonomous deposition robots, the deposition instructions comprising a deposition arrangement height parameter, wherein the deposition height parameter is based on the profile of the ground surface. [0070] System 700 may utilize a computer vision system, for example a camera or sensor array arranged to detect uneven ground or ground undulations. The camera may be located on the traverse guide 62 along with the nozzle array 42 or supported by the chassis 12. The traverse guide permits movement of the nozzle array in the second direction beyond the width of the ground wheel arrangement, W, known as the operational width 68. In some examples, the traverse guide is fixed in relation to the ground wheel arrangement, such that they are not movable relative to one another in the first direction. In some examples, the traverse guide is movable relative to the ground wheel arrangement in the second direction, so that material can be deposited an area while the ground wheel arrangement is stationary.

[0071] In some examples, the sensor arrangement comprises a light source, and the control unit is further configured to: instruct the sensor arrangement to irradiate the ground surface with light from the light source; detect a luminance reflected from the ground surface irradiated with light from the first light source; calculate a distance from the light source to the ground surface, and amend the deposition head height parameter based on the calculated distance.

[0072] The autonomous deposition robots 710, 720 can also deposit material wider than the width W of the ground wheel arrangement 24 and when an entire strip of the image has been printed, for example, turn around to print an adjacent strip, in the art this is known as ‘tiling’. In this way, the ground wheel arrangement 24 does not run over any part of the freshly painted ground, the outer tracks of the ground wheel arrangement 24 is seen to be well within the width of the strips.

[0073] In some examples, the deposition head further comprises a print rack, the print rack comprises at least a horizontal rail, arranged orthogonal to the direction of movement of the printing device; a vertical rail, arranged orthogonal to the horizontal rail; and wherein the deposition head is affixed to the vertical rail.

[0074] The system 700 may a sensor, such as a crop edge detector, mounted on the harvester for measuring the ground contour of an area a substantial distance in front of the header and providing a surface profile indication over the whole platform width. The sensor includes a transmitter mounted on the autonomous deposition robot for radiating a signal across an area approximately equal to the width of the path to be traversed by the header, and a receiver which receives reflected signals. Travel times of the signals from a radiated area in the path are utilized to estimate the ground contour of that area.

[0075] The ground contour can be estimated directly by scanning the uneven ground with a signal, such as a high-frequency radar signal, and receiving reflections from the ground. In some examples, a crop contour signal can be used to maintain the header a preselected distance below the crop heads to reduce throughput. The crop contour signal can also be used to estimate the ground surface profile.

[0076] An onboard processor calculates the desired header height for an area in advance of the system 700 reaching the area. The early ground contour enables the height control to begin to make corrections in advance of the header reaching the area for smoother adjustments with less stress on harvester components. Hydraulic power requirements and header reaction response time are reduced, features which are particularly important when the autonomous deposition robot is operated at relatively high speeds or in fields with abruptly changing ground surface contours. The contour prediction may also be used to compensate for the effects of header attitude changes resulting from harvester ground wheels or tracks riding on that contour.

[0077] FIG. 8 is a schematic diagram of an exemplary apparatus for depositing materials on an uneven ground surface, in accordance with at least one of the examples described herein. A compressor (e.g., an air compressor) 810 is fluidly connected to a solenoid 820 and solenoid valve 822 to provide an air supply 815. The air supply dispenses the material from dispenser 824. Controller 850 and battery 855 are electrically connected through wires 852 to the solenoid valve 822 and compressor 810, as well as the other components, as described below. The controller 850 provides control to devices and the battery 855 provides power, however, the battery may be replaced or used in conjunction with a “shoreline” power system, mains power, or the like. A hopper 832, comprising the material (e.g., a paint in liquid, resin or powder form ready to be mixed and deposited) is fluidly connected to a pump/extruder 834, controllable by controller 850 through wires 852 (from point A to point A’) to pump the material through a hose 836 to the solenoid 820 and solenoid valve 822. In some examples, the compressed air provided by compressor 810 atomises the material into a spray as a deposition modality. In some examples, hose 836 comprises insulation, heating elements, or a combination thereof.

[0078] Compressor 810, air supply 815, solenoid 820, solenoid valve 822, dispenser 824, hopper 832, pump/extruder 834, and hose 836 are collectively referred to as the deposition system. A baffle 840 is utilized to separate the deposition system from an optional treatment system. The optional treatment system may be used for pre-treatment or after-treatment of the ground surface. The treatment system comprises a ground temperature sensor 860, for example, an IR temperature sensor; a heater 872, which may be a ground fan heater, a microwave heater, or an open flame gas torch; a vacuum ground cleaner 874. [0079] A rotary encoder 880 which may be a mechanical, optical, on-axis magnetic, or off-axis magnet rotary encoder; absolute or incremental, is also provided on the apparatus. The rotary encoder 880 is used for converting the angular position or motion of a shaft or axle to analogue or digital output signals; useful for knowing the position of the deposition head, and position of the autonomous (or semi-autonomous) device. For example, an optical encoder uses light shining onto a photodiode through slits in a metal or glass disc. Reflective versions also exist. This is one of the most common technologies. However, optical encoders are sensitive to dust, which may be a problem with outside agricultural uses. Power from battery 855 and control from controller 850 is delivered to the treatment system by wires 852. That is to say that the components of the aftertreatment system are electrically connected to the controller 850 and the battery 855.

[0080] Mixing and agitating equipment may be incorporated into the hoppers 832. Such equipment, such as kettles, must be equipped with material agitators to prevent hardening in the liquid phase and must be capable of thoroughly mixing the material at a rate which will ensure even disbursement and uniform temperatures throughout the material mass.

[0081] FIG. 9 is a schematic diagram of an exemplary autonomous system for applying the material to uneven ground, in accordance with at least one of the examples described herein. The autonomous printing system 900, comprises driving means 910, which may be independently controllable motors affixed to wheels. The driving means 910 moves the autonomous system across the ground surface. The autonomous system may be semi- autonomous. In the present disclosure semi-autonomous refers to devices and systems that require minimum human intervention and utilise advanced driver assist technologies, such as adaptive cruise control, lane keeps assist, and intelligent park assists, to reduce the effort required to manoeuvre the autonomous system and create the desired ground markings. Autonomous refers to devices and systems that are capable of manoeuvring without a human operator. The Society of Automotive Engineers (SAE) International and the US National Highway Traffic Safety Administration (NHTSA) have defined five different levels of semi- autonomous and autonomous vehicles based on the amount of human intervention required. The autonomous system comprises the exemplary apparatus for applying ground markings as described with reference to FIG. 10.

[0082] FIG. 10 illustrates a block diagram 1000 of computing module 1002, in accordance with some embodiments of the disclosure. In some examples, computing module 1002 may be communicatively connected to a user interface. In some examples, computing module 1002, may be the controller of the apparatus 1000 as described with reference to FIG. 10. In some examples, computing module 1002 may include processing circuitry, control circuitry, and storage (e.g., RAM, ROM, hard disk, a removable disk, etc.). Computing module 1002 may include an input/output, I/O, path 1006. I/O path 1020 may provide device information, or other data, over a local area network (LAN) or wide area network (WAN), and/or other content and data to control circuitry 1010, which includes processing circuitry 1014 and storage 1012. Control circuitry 1010 may be used to send and receive commands, requests, signals (digital and analogue), and other suitable data using I/O path 1020. I/O path 1020 is connected to control circuitry 1010 (and specifically processing circuitry 1014) to one or more communications paths. In some examples, computing module 1002 may be an on-board computer of the apparatus for paint markings, such as apparatus 1000. The controller is configured to carry out any of the methods disclosed herein, for example, the control circuitry 1010 is operable to receive an image to be printed, slice the image into a plurality of segments to be printed, and control the dispenser to deposit material forming the image.

[0083] Control circuitry 1010 may be based on any suitable processing circuitry such as processing circuitry 1014. As referred to herein, processing circuitry should be understood to mean circuitry based on one or more microprocessors, microcontrollers, digital signal processors, programmable logic devices, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), etc., and may include a multi-core processor (e.g., dual-core, quad-core, hexa-core, or any suitable number of cores) or supercomputer. In some examples, processing circuitry may be distributed across multiple separate processors or processing units, for example, multiple of the same type of processing units (e.g. two Intel Core i7 processors) or multiple different processors (e.g., an Intel Core i5 processor and an Intel Core i7 processor). In some examples, processing circuitry 1014 executes instructions for computing module 1002 stored in memory (e.g., storage 1012).

[0084] The memory may be an electronic storage device provided as storage 1012, which is part of control circuitry 1010. As referred to herein, the phrase "electronic storage device" or "storage device" should be understood to mean any device for storing electronic data, computer software, or firmware, such as random-access memory, read-only memory, hard drives, solid- state devices, quantum storage devices, or any other suitable fixed or removable storage devices, and/or any combination of the same. Non-volatile memory may also be used (e.g., to launch a boot-up routine and other instructions). Storage 1012 may be sub-divided into different spaces such as kernel space and user space. Kernel space is a portion of memory or storage that is, e.g., reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. User space may be considered an area of memory or storage where application software generally executes and is kept separate from kernel space so as to not interfere with system-vital processes. Kernel mode may be considered as a mode when control circuitry 1010 has permission to operate on data in kernel space, while applications running in user mode must request control circuitry 1010 to perform tasks in kernel mode on its behalf.

[0085] Computing module 1002 may be coupled to a communications network. The communication network may be one or more networks including the Internet, a mobile phone network, mobile voice or data network (e.g., a 3G, 4G, 5G or LTE network), mesh network, peer-to-peer network, cable network, cable reception (e.g., coaxial), microwave link, DSL reception, cable internet reception, fibre reception, over-the-air infrastructure or other types of communications network or combinations of communications networks. Computing module 1002 may be coupled to a secondary communication network (e.g., Bluetooth, Near Field Communication, service provider proprietary networks, or wired connection). Paths may separately or together include one or more communications paths, such as a satellite path, a fibre-optic path, a cable path, a path that supports Internet communications, free-space connections (e.g., for broadcast or other wireless signals), or any other suitable wired or wireless communications path or combination of such paths.

[0086] In some examples, the control circuitry 1010 is configured to carry out any of the methods as described herein. For example, storage 1012 may be a non-transitory computer- readable medium having instructions encoded thereon to be carried out by processing circuitry 1014, which cause control circuitry 1010 to carry out a method for marking defects on a ground surface with an autonomous deposition robot.

[0087] It should be understood that the examples described above are not mutually exclusive with any of the other examples described with reference to FIGS. 1 - 10. The order of the description of any examples is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

[0088] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

[0089] This disclosure is made to illustrate the general principles of the systems and processes discussed above and is intended to be illustrative rather than limiting. More generally, the above disclosure is meant to be exemplary and not limiting and the scope of the disclosure is best determined by reference to the appended claims. In other words, only the claims that follow are meant to set bounds as to what the present disclosure includes.

[0090] While the present disclosure is described with reference to particular example applications, it shall be appreciated that the disclosure is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the present disclosure. Those skilled in the art would appreciate that the actions of the processes discussed herein may be omitted, modified, combined, and/or rearranged, and any additional actions may be performed without departing from the scope of the disclosure.

[0091] Any system feature as described herein may also be provided as a method feature and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure. It shall be further appreciated that the systems and/or methods described above may be applied to, or used in accordance with, other systems and/or methods.

[0092] Any feature in one aspect may be applied to other aspects, in any appropriate combination. In particular, method aspects may be applied to system aspects, and vice versa. Furthermore, any, some, and/or all features in one aspect can be applied to any, some, and/or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspect can be implemented and/or supplied and/or used independently. EXAMPLES

[0093] Illustrative examples of the technologies described herein are provided below. An embodiment of the technologies may include any one or more, and any combination of, the examples described below:

Example 1 describes a computer-implemented method of determining deposition instructions for an autonomous deposition robot on an uneven ground surface, the method comprising: driving the autonomous deposition robot in a first direction; detecting a first profile of the ground surface in a second direction, perpendicular to the first direction; and determining deposition instructions for the autonomous deposition robot, the deposition instructions comprising a deposition head height parameter, wherein the deposition head height parameter is based on the profile of the ground surface.

Example 2 includes the subject matter of Example 1, and further comprises scanning the deposition head in the second direction above the ground surface.

Example 3 includes the subject matter of any previous Example, wherein the profile of the ground surface is detected while the deposition head is scanned in the second direction.

Example 4 includes the subject matter of any previous Example, and further comprises depositing material on the ground surface according to the deposition instructions.

Example 5 includes the subject matter of any previous Example, wherein the deposition on the ground surface is carried out in a plane corresponding to the first profile.

Example 6 includes the subject matter of any previous Example, and further comprises detecting a second profile of the ground surface, parallel to and abutting the first profile.

Example 7 includes the subject matter of any previous Example, wherein the second profile of the ground surface and the deposition of material on the ground surface are carried out in parallel.

Example 8 includes the subject matter of any previous Example, wherein the deposition instructions comprise a plurality of substantially equal-sized cells located over the ground surface, each cell having a deposition head height parameter.

Example 9 includes the subject matter of any previous Example, wherein each row of the substantially equal-sized cells are parallel to the second direction, and each column is parallel to the first direction.

Example 10 includes the subject matter of any previous Example, further comprises advancing the driving of the autonomous deposition robot in the first direction in steps equal to the size of the substantially equal-sized cells in the deposition instructions. Example 11 includes the subject matter of any previous Example, and further comprises sending the deposition instructions to at least one other autonomous deposition robot.

Example 12 includes the subject matter of any previous Example, wherein the depositions instructions are user-originated via a cloud server or device, or an edge server or device.

Example 13 includes the subject matter of any previous Example, wherein the detecting a profile of the ground surface comprises: irradiating the ground surface with light from a light source; detecting a luminance reflected from the ground surface irradiated with light from the first light source; calculating a distance from the light source to the ground surface based on the detected luminance; and amending the deposition head height parameter of the deposition instructions based on the calculated distance.

Example 14 describes a system for determining deposition instructions for a plurality of autonomous deposition robots on an uneven ground surface, wherein the multiple autonomous deposition robots are operable to deposit material on the uneven ground surface, the system comprising: a first autonomous deposition robot, and a second autonomous deposition robot, wherein each autonomous deposition robot comprises: at least one receptacle to hold a deposition material; at least one deposition arrangement; a locomotion arrangement; a sensor arrangement; a control unit, the control unit configured to: instruct the locomotion arrangement to drive the autonomous deposition robot in a first direction; instruct the sensor arrangement to detect a first profile of the ground surface in a second direction, perpendicular to the first direction; and determine deposition instructions for the autonomous deposition robots, the deposition instructions comprising a deposition arrangement height parameter, wherein the deposition height parameter is based on the profile of the ground surface.

Example 15 includes the subject matter of Example 14, wherein the sensor system comprises a computer vision system.

Example 16 includes the subject matter of Example 14 or 15, wherein the computer vision system comprises a camera.

Example 17 includes the subject matter of any of Examples 14 to 16, wherein the locomotion arrangement is a ground wheel arrangement.

Example 18 includes the subject matter of Examples 14 to 17, and further comprises a chassis with a nozzle array on a traverse guide, the traverse guide permitting movement of the nozzle array in the second direction beyond the width of the ground wheel arrangement. Example 19 includes the subject matter of Examples 14 to 18, wherein the traverse guide is fixed in relation to the ground wheel arrangement.

Example 20 includes the subject matter of Examples 14 to 19, wherein the traverse guide is movable relative to the ground wheel arrangement in the second direction, so that material can be deposited an area while the ground wheel arrangement is stationary.

Example 21 includes the subject matter of Examples 14 to 20, wherein the material for deposition is a herbicide, pesticide, insecticide, plant growth aid, water or marking material.

Example 22 includes the subject matter of Examples 14 to 21, wherein the marking material is paint, ink, coloured material, or powder.

Example 23 includes the subject matter of Examples 14 to 22, wherein the sensor arrangement comprising a light source, the control unit further configured to: instruct the sensor arrangement to irradiate the ground surface with light from the light source; detect a luminance reflected from the ground surface irradiated with light from the first light source; calculate a distance from the light source to the ground surface; and amend the deposition head height parameter based on the calculated distance.