WO2023180772A2

WO2023180772A2 - A system and method for the preparation of paints for autonomous ground printing machines

Info

Publication number: WO2023180772A2
Application number: PCT/GB2023/050765
Authority: WO
Inventors: Anthony David George Rhoades; Samuel Paul CORNISH-EVANS; Jiri DOHNALEK; Lewis CASSIDY
Original assignee: Micropply Limited
Priority date: 2022-03-25
Filing date: 2023-03-24
Publication date: 2023-09-28
Also published as: WO2023180772A3

Abstract

Apparatus suitable for use in an autonomous or semi-autonomous ground printing machine, the apparatus comprising: a first receptacle comprising a first colorant substance, the first receptacle fluidly connected to a first dispenser; a second receptacle comprising a second colourant substance, the second receptacle fluidly connected to a second dispenser; an output fluidly connected to the first and second dispensers; a controller unit, the controller unit able to take as an input, information about a required characteristic of a paint product; wherein the controller unit is operable to calculate the quantities of the first colourant substance and the second colourant substance required to form the paint product, and is operable to control the first and second dispensers to output the required quantities of the first colourant substance and the second colourant substance. Thus, the autonomous dispensing machine is able to dispense a wide variety of paint finishes and types in a just in time manner, in any quantity required, removing the need to dispense into or using a pre- determined or pre-mixed white base paint.

Description

A SYSTEM AND METHOD FOR THE PREPARATION OF PAINTS FOR AUTONOMOUS GROUND PRINTING MACHINES

The present invention provides an autonomous ground printing and deposition machine, where paint and if needed, other materials, are mixed just in time in the shades, quantities and with the precision required. Specifically, it relates to the inline mixing of colourant materials in just-in-time quantities and shades for ground printing applications.

Ground printing is a process which has been in use for decades, with little technological advancement. Ground marking is typically carried out manually. The process is simple yet time consuming with high quantities of man hours used to produce logos or markings. The accuracy of these markings depends upon the worker, or the stencil used. It requires significant planning, the manufacture of pre-ordered plastic stencils, and large teams of workers to decipher instructions, prepare, lay out and complete a site for marking. Where marking is required such as for logos, safety or hazard signs, the complex make-up of these images mean that difficulties persist to print any image, any size, any colour, directly onto any ground surface without a significant cost of time, expense, and compromise in image attributes, such as resolution.

One approach to automating ground marking is found in US 2005/0055142 Al in which a remotely controlled turf image marker comprises a ground maintenance vehicle adapted to both mow and store grass as well as carry a marking device that includes a delivery system for applying a marking material to the ground. Dispensing devices for putting down marking materials are provided in the form of boxes requiring mechanisms that need to be driven by a motor, such as an electric, air or another fluid motor. WO 2002/28541 shows a GPS- controlled vehicle for printing logos over a wide area such as the runoff for a racing track. However, such systems demand specialist control and have limited resolution.

Other patent applications from the Applicant describe various systems and improvements over the art, describing autonomous robots that can print markings direct -to-ground from a complex input image. Such systems of the applicant currently require one paint tank per colour, ideally with enough pre-mixed paint to complete a full image print, in order to avoid unnecessary travel for the ground printer and time wasted doing so. The paint tanks must be pre-selected and inserted prior to a print, in order to match the colours in the required print image.

It is desirable to make ground marking or depositing materials on the ground as efficient as printing, or marking, on paper, with high resolution of marking and in multiple colour shades.

Summary of Invention/Advantages

In a first aspect of the present invention, there is provided apparatus suitable for use in an autonomous or semi-autonomous ground printing machine. The apparatus comprising a first receptacle suitable for containing a first colourant substance, the first receptacle fluidly connected to a first dispenser; a second receptacle suitable for containing a second colourant substance, the second receptacle fluidly connected to a second dispenser; an output fluidly connected to the first and second dispensers; a controller unit, the controller unit able to take as an input, information about a required characteristic of a paint product; wherein the controller unit is operable to calculate the quantities of the first colourant substance and the second colourant substance required to form the paint product, and is operable to control the first and second dispensers to output the required quantities of the first colourant substance and the second colourant substance.

In a second aspect of the present invention, there is provided a method of creating paint for use in an autonomous or semi-autonomous ground printing machine. The method comprises taking as an input, information about a characteristic of a paint product; calculating the required quantity of a first colourant substance and the required quantity of a second colourant substance to form the paint product; and controlling a first and second dispensing means to output the required quantity of the first colourant substance and the required quantity of the second colourant substance to form the paint product; wherein in operation, the paint product is used in a ground printing application.

In a third aspect of the present invention, there is provided an autonomous or semi- autonomous ground printing machine, comprising: navigation means; locomotion means; paint deposition apparatus; a first receptacle suitable far containing a first colourant substance, the first receptacle fluidly connected to a first dispenser; a second receptacle suitable for containing a second colourant substance, the second receptacle fluidly connected to a second dispenser; an output fluidly connected to the first and second dispensers; and a controller unit, the controller unit able to take as an input, information about a required characteristic of a paint product; wherein the controller unit is operable to calculate the quantities of the first colourant substance and the second colourant substance required to form the paint product, and is operable to control the first and second dispensers to output the required quantities of the first colourant substance and the second colourant substance, via the output, to the paint deposition arrangement.

In some examples, according to the first, second or third aspects, both the first and second colourant substances comprise a paint base.

In some examples, the method or apparatus further comprises an internal chamber, wherein the internal chamber is fluidly connected between the first and second dispensers and the output. In some examples, according to the first or second aspect, the internal chamber is fluidly sealed.

In some examples, according to the first, second or third aspects, the dispensing means comprises a solenoid, hydraulic pump and/or actuator valve.

In some examples, according to the first, second or third aspects, the controller can further control the timing of the first and second dispensers to create a mix of the first colourant substance and the second colourant substance.

In some examples, according to the first, second or third aspects, injected air is used to create a mix of the first colourant substance and the second colourant substance.

In some examples, the method or apparatus further comprises a mechanical mixer unit.

In some examples, according to the first, second or third aspects, the first and/or second receptacles comprise a flexible bag, the flexible bag provided with an airtight valve outlet sealed to the flexible bag and wherein the flexible bag is housed within a substantially rigid frame within the autonomous or semi-autonomous dispensing machine.

In some examples, the method or apparatus further comprises one or more cleaning fluid supply conduits, wherein the one or more cleaning fluid supply conduits are opening in the one or more dispenser heads at a cleaning fluid inlet in the internal chamber.

In some examples, the method or apparatus further comprises a choice of multiple paint products and entry via an input.

In some examples, according to the first, second or third aspects, the characteristic comprises one or more of finish, viscosity, particle size, solubility, luminosity, colour, and/or quantity.

In some examples, according to the first, second or third aspects, either the first colourant substance and/or the second colourant substance is one or more of a paint, a paint concentrate, an ink, an ink concentrate, a pigment, a coloured material, a paint powder.

Thus, the present invention relates to an in-line mixing system for an autonomous ground printer, which can not only dispense white when required but can also water down the base paints to the right consistency for the print required (dependent on the ground formation to be printed upon), as well as produce lighter colours when the image dictates. Thus, not only allowing in-line mixing of colours that are not loaded into the tanks of the ground printer, but also being able to compensate for a large amount of white and pale colour deposition.

The paints used in ground printing are different in comparison with other printing applications, as they need to be removed easily after a print (to get ready for the next use of the stadium), and so they use a large amount of water. The paints used in ground printing are usually watered-down acrylic paints.

DESCRIPTION OF FIGURES

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 - is a schematic diagram of front view of an exemplary autonomous deposition machine of the present invention;

Figure 2 - illustrates a cut-away rear view of the autonomous ground printer of Figure 1;

Figures 3a & 3b are illustrations of a planar view of the autonomous ground printer of Figure 1;

Figure 4 is an illustration of a rear view of the autonomous ground printer of Figure 1 connected to a cloud network;

Figure 5 - is a schematic diagram of primary colourant packaging comprising a flexible bag with a hose which may be used in the autonomous deposition machine of Figure 1 of the present invention;

Figures 6a and 6b - are schematic diagrams illustrating a colour creation apparatus, as can be used in the autonomous deposition machine of Figures 1 to 5 of the present invention;

Figure 7 is a schematic diagram illustrating a vortex/swirl mixing chamber which may be used with the embodiment of Figure 6 of the present invention;

Figure 8 - is a process flow diagram illustrating a first embodiment of a colourant processing method of the present invention;

Figure 9 - is a process flow diagram illustrating a first embodiment of a colourant processing method of the present invention; and

Figure 10 - is a flow diagram illustrating an output comparison method, according to an embodiment of the present invention. 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 printer are not necessarily to scale and may just be representative of components of the ground print machines, or other described entities.

DETAILED DESCRIPTION

Figure 1 is a schematic diagram illustrating a front view of an exemplary autonomous ground deposition machine, comprising an improved colour mixing system of the present invention. There is shown an autonomous ground marking machine 10 comprising a case 12 held securely by a chassis (not shown) supporting the ground wheel arrangement 24 (a, b, c, d) with a print head 60 on a traverse guide 62.

The autonomous ground deposition machine 10 has wheels 24 (a, b, c, d, with only a and c shown in Figure 1) for movement, a navigation module 38 and may comprise a laser 40. The navigation module 38 can include a Global Positioning Device, computer vision, or a laser 40, for navigation on a ground surface to be marked. In some examples, the autonomous ground deposition machine 10 carries out triangulation/trilateration using the laser 40 for positioning, along with reflectors (not shown), as described in the Applicant's prior applications. In some examples, in conjunction with algorithms such as simultaneous, learning and mapping algorithms (SLAM), computer vision is used to identify, map, and navigate the ground surface. In operation, the autonomous ground deposition machine 10 may be in constant communication with a positioning device and may also reposition itself based on communication from a Global Positioning Device.

In Figure 2, there is illustrated an autonomous ground-marking robot or distributed deposition robot 10 comprising an outer case 12 cut away to reveal an array of primary packaging in the form of reservoirs 5a, 5b, 5c & 5d. The reservoirs 5a-d may contain different colours of marking materials, i.e. inks or paints, which 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 a nozzle array - see Fig 3), 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. Each reservoir 5a, 5b, 5c & 5d is supported on a weight-measuring plate 14a, 16a, 18a and 19a connected to an on-board control system 22, which may comprise communication means such as a transceiver 22a. Each weight-measuring plate 14a, 16a, 18a and 19a is an integral part of a frame 26 capable of holding the reservoir 5 firmly in place.

During printing or ground marking the weight of the reservoirs 5a, 5b, 5c & 5d will decrease as ink is deposited onto the ground. The weight monitoring plates 14a, 16a, 18a and 19a can measure their change in weight and gather data. For example, the data could be used to alert a user when a reservoir 5 needs replacing, because it is nearly empty.

Each reservoir is connected to the colour creation apparatus (of Figure 6) of the present invention by nozzle output 34. At least one water tank 20, fluidly connected to reservoirs Sari, is shown which may be used to dilute the paint concentrates held in the reservoirs 5 in order to create various shades required for the specific printing application.

The on-board computer 22, utilises an improved colour mixing system, as described with reference to Figures 8, 9 & 10 of the present invention. This improved colour mixing system enables several thousands of colours to be produced from an RGB input but is also specially adapted for white and pale colour deposition.

As can be seen in Figures 3a & 3b, the autonomous ground marking machine 10 comprises the case 12 held securely by a chassis supporting the ground wheel arrangement 24 with a print head 60 on a traverse guide 62, the traverse guide 62 permitting movement of the print head 60 beyond the width W of the ground wheel arrangement 24, along the length of the print width 68. A nozzle array 42 may be attached to the print head 60. The nozzles in the array 42 maybe fixed and the print head 60 moveable. The print head 60, via the print guide 62, may be moveable along the length of a print width 68, which is the area the print head 60 is capable of printing. The print head 60 may also be movable vertically (i.e., in a z-direction) based on the image to be printed, for example, the print head 60 can be moved up and down depending on the density of the image to be printed.

The ground wheel arrangement 24 comprises wheels 24a, 24b, 24c and 24d to steer the autonomous ground marking machine 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 control system 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 machine 10 forward for it to then print another line.

In Figure 4, the system controller 22 may be in communication with the cloud 100, the edge 102, such as remote resource, which may be a tablet, smartphone or laptop when the present techniques are applied. The edge 102 may be a tablet controlled by a user or operator.

Specifically, there is also shown a navigation module 38 (also shown in Figure 1), which is coupled to a system controller 22, which is in communication, via transceiver 22a, with a cloud network 100, and an edge device 102, which may be a tablet, smartphone or laptop when the present techniques are applied. The edge device 102 may be a tablet controlled by a user, such as a Groundsman located on-site responsible for ground markings of a pitch within, for example, a football or rugby stadium.

In some examples, system controller 22 may include processing circuitry, control circuitry, and storage (e.g., RAM, ROM, hard disk, a removable disk, etc.) System controller 22 may include an input/output, I/O, path. The I/O path 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, which includes processing circuitry and storage. Control circuitry may be used to send and receive commands, requests, signals (digital and analogue), and other suitable data using I/O path. I/O path is connected to control circuitry (and specifically processing circuitry) to one or more communications paths. 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. Nonvolatile memory may also be used (e.g., to launch a boot-up routine and other instructions). In the present example, it will be appreciated that the cloud 100 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 ground marking machine 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). In some examples, or the system controller 22 or cloud 100 executes/provides instructions for the autonomous ground marking machine 10.

In the present example, the autonomous ground marking machine 10 is configured to connect with the cloud 100 or the edge 102 to push data thereto, as well as receive data. It will be appreciated that the autonomous ground marking machine 10 may connect to the cloud 100 or the edge 102, e.g. via the internet, using one or more nodes/routers in a network e.g. a mesh network. The connection 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. The autonomous ground marking machine 10 may be coupled to a secondary communication network (e.g., Bluetooth, Near Field Communication, service provider proprietary networks, or wired connection) to push data thereto, as well as receive data. 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. In the present example, it will be appreciated that the cloud 100 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 colourant dispensing machines of the present invention.

A user wishing to access the data at the cloud 100 or edge 102 may do so subject to user privileges and subscription services using a client device 106 such as smartphone or tablet. In an illustrative example, the user may connect to the cloud 100 or edge 102 using a browser on the client device 106, whereby, for example, whereby clicking a link in the browser will cause the client device 106 to fetch the data from the cloud 100 or edge 102, which in the present example is a web-application 108.

As best seen in Figure 5 of the present invention, an autonomous ground marking machine 10 is shown which can mix and if needed, dilute, a required quantity of paint on demand. Wherein the autonomousground marking machine lO comprises a reservoir 5a, which further comprises a flexible ink bag 28 and which is adapted to store a paint concentrate 500. In the present embodiment, the paint concentrate 500 includes a paint resin and a paint pigment at high percentage of solids, without water, as its major ingredients by weight.

The autonomous ground marking machine 10 of the present invention mixes the paint concentrate 500 with water 502 flowing through the autonomous ground marking machine 10 to form a paint suitable for application to a printable ground surface. In some examples, the autonomous ground marking machine 10 mixes the paint concentrate 500 in a first in-line mixer unit 35, prior to depositing the mixed paint. The reservoirs 5a comprise the flexible ink bag 28 connected to the first in-line mixer unit 35, via a hose 36. The first in-line mixer unit 35 is optional, in some examples, the mixing occurs only in second mixer unit 300, as will be described in more detail below.

The flexible ink bag 28 may contain different colours of marking materials, i.e. inks or paints, which may comprise CYM or, if good black is required, CYMK colours. Since the substrate or ground to have these deposited upon is not likely to be white, a white may be required for any print that has white or a paler shade than the colours contained in the flexible ink bag 28. The flexible ink bag 28 here contains the magenta ink (M) suitable for depositing a magenta colour on a ground, though in general it may contain 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, or the like, provided that a compatible hose 36, mixer 35 and nozzle arrays 42 are attached.

The hose 36 is further connected to a control means 44a-b, such as solenoid and/or solenoid valve, fluidly connected to a water tank 20 containing water used to flush the hose 36 and nozzles 42 of Figure 3 and using the embodiment of Figure 6, is able dilute the paint concentrate or other ground deposition material, by suitable mixing.

The control means 44b, fluidly connected to water tank 20 containing water, is operable to flush hoses, such as hose 36 and 52. In some examples, control means 22 can increase or decrease the shade of the ink or ground marking material by controlling the control means 44a-b to provide various levels of concentrate 500 and water from water tank 20. Thereafter, the water and concentrate 500 mix in the first mixing unit 35, second mixing unit 300, or swirl chamber 160, or a combination thereof.

The reservoirs 5a comprising the flexible ink bags 20 are connected to a nozzle array 42, after the second mixer unit 300 (the mixer unit of Figure 7). Each flexible ink bag 20 of the reservoirs 5a, 5b, 5c & 5d is fluidly connected to the second helical mixer unit 50, after the first in-line mixer unit 35, via secondary hose 52. Ultimately, the components are all fluidly connected to the nozzle array 42.

Here the nozzle array 42 acts as the means to deposit the material for deposition. Any such suitable nozzle, nozzle array or means to deposit the material, depending on the actual material to be deposited, may be used.

It will be appreciated that if using more than one colorant in a single mixer unit of any of the embodiments from Figures 3 to 7 included, the internal chambers and fluid outlets of the mixer units and/or related pipe work needs to be cleaned after each dispensing operation to avoid mixing of colorant from a previous dispensing operation with those of a succeeding operation. Such purging and cleaning operations are discussed in other co-pending applications by the Applicant. Figures 6a and 6b - are schematic diagrams of a colour dispensing and mixing apparatus, as can be used in the autonomous ground deposition machine of Figures 1 to 5 of the present invention. There is shown a second mixer unit 300 with an outer casing 310 and internal chamber 330, into which paint, or colourant materials, are injected via dispenser heads (320 a, b, c). Gravity fed systems may also be used to input the materials.

The materials may be dispensed or injected in a sequential order, for example clockwise or counter-clockwise, which would cause a swirl motion and this sequence would be controlled by the system controller 22 of Figure 2. Additional injected air or water under pressure may also be used to create an additional, or larger, swirl motion enough to further mix the injected materials. Alternatively, a solvent and/or water may be injected in sequence to dilute the materials, or for other suspension reasons and thus being added at the same time and in the required amount, may also cause a mix to occur. The ratios of which being precisely calculated using the methods described in Figure 9.

It should be clear to someone skilled in the art that there need to be enough dispenser heads (320 a, b, c), one each for base paint colours, or substance to be dispensed, as well as one for the water and/or chemical cleaning (330). The results are output via nozzle 340 to a print head 60 comprising nozzles array 42 (as described in Figures 1 to 5).

Water and/or other suitable chemicals may also be used after the dispensing sequence, in order to clean the internal chamber 310 and be exited by a separate flush output 350, when used for cleaning. As it might not be desirable for the resulting chemicals to go into the printhead. Each dispenser head (320 a, b, c) is controlled by a solenoid or other control means (not shown), all of which may be controlled by the system controller 22 of Figures 2, for example, or via separate processing means.

The second mixer unit 300 (also referred to as a colour dispensing and mixing apparatus) can be used for paints, inks, or epoxy resin dispensing and mixing, for example. In some examples, the second mixer unit 300 is fluidly connected to swirl chamber 160 of Figure 7 for example if further mixing is required, shown by marker "A". Other mechanical paint mixing methods are also known in the art.

Figure 7 - is a schematic diagram of a vortex/swirl mixing chamber which may be used with the embodiment of Figure 6 of the present invention. Swirl chamber 160 is disposed downstream of second mixer unit 300, as shown by marker "A". Figure 7 comprises a swirl chamber 160, with four air inlets 162, 163, 164, 165 offset on the side of the swirl chamber 160, which in operation to create a tornado effect. A fifth air inlet 167 at the top of the swirl chamber 160, drawers air down to create a Venturi effect at the lower end.

In some examples, the second mixer unit 300 may be bypassed, and the paint or inks are mixed directly in the swirl chamber 160. For example, powder paint, or paint concentrate may be injected via separate hydraulic lines 169 into the main chamber 160 and is mixed by the air in the vortex and output by a nozzle output valve 168.

Paint pigments are powders of typically small size that tend to 'stick together' to form clumps or agglomerates. These must be broken down into separate particles that must then be wetted by resin and additives to stop them sticking together again. This is the process of dispersion. High speed mixers are used for combining materials and dispersing most pigments. Thus, if paint concentrates are being used, then improved performance may be obtained by using an atomiser on each input 169 in order to atomise the paint so that it mixes properly and doesn't stick or attach to the sides of the swirl chamber 160. The inner lining of the swirl chamber 161 could also be made from non-stick material, such as PTFE, so that the paint doesn't stick to it the inside of the swirl chamber 160. The chamber 160 itself could be made from metal or another type of plastic, whichever suits the scale and application of the vortex mixer.

The air inputs 162, 163, 164, 165 are pressurised. If the paint powder needs mixing further, the air inlets 162, 163, 164, 165 could also take in pressurised water, solvents, binders or stabilisers, or pressurised white paint, depending on the application. In some applications, pigments need to be added slowly to a portion of the liquid paint components, with the mixer running, so there is a need to accurately enable the control of the paints flow rate. By controlling the flow rate, the system can control the ratios and amounts of the colours very easily and accurately.

It should be clear to those skilled in the art, that many means can be used to control the flow of the colour dispensing system as shown in Figures 3 to 5, such as a solenoids, hydraulic pumps and/or actuator valves. Any combination of said devices can be used to dispense a mixture of chemicals, such as solvents, binders and stabilisers, concentrates and water, or other fluids for the correct mixing application.

Acrylic based paints can be used, as the paint is water based and can be heavily diluted to improve its flow. All paints have colour pigments in them; these pigments are what gives the paint its colour. Watering the paint down reduces the density of the pigments in the paint so, when the paint mixes, it may not produce the exact colour on first time use, so a feedback loop, as described below with reference to Figure 10 below might need to be deployed.

It will be appreciated that if using more than one colorant in a single mixer unit of any of the embodiments from Figures 3 to 6 included, the internal chambers and fluid outlets of the mixer units and/or related pipe work may need to be cleaned after each dispensing operation to avoid mixing of colorant from a previous dispensing operation with those of a succeeding operation. Such purging and cleaning operations are discussed in other co-pending applications by the Applicant. It should be clear to someone skilled in the art that there are various mechanical options for mixing the required quantities and finish of paint required, depending upon the application.

It will also be appreciated that first mixing unit 35, second mixing unit 300 and swirl chamber 160 all incorporate the same basic concept of calculating the required quantity of a first colourant substance and the required quantity of a second colourant substance to form a paint product and controlling a first and second dispensing means to output the required quantity of the first colourant substance and the required quantity of the second colourant substance to form the paint product. In particular, the paint product may be used in a ground printing application.

Figure 8 is a process flow diagram illustrating a first embodiment of a colourant processing method of the present invention. The steps of the process flow in Figure 8 shall herein be described.

Process Start:

Step 1: Obtain Required Output Colour values, volume and finish of paint required

Via a system controller 22, such as that described in Figure 2, an input can be obtained, which describes the characteristics, such as colour of a paint or ink to be mixed, as well as the consistency, such as viscosity or solubility (see Step 5 below). For example, a system user would simply be asked via an input (such as keypad or a touch capable display screen), the volume, type (such as Matt, or Silk, Indoor or Outdoor) and colour shade of the paint to be mixed. The user may provide a pantone reference or an RGB colour vector, which is handled in Step 2 following.

Step 2. Convert Required Output Colour values to Machine values (optional step)

In colourant mixing and/or printing apparatus, colour conversion is often required. Many colour space systems are used in the art, for example use RGB, CMY, Pantone. For example in the art, a RGB input is usually inputted by a user, or in a file, comprising a vector of three numbers varying between 255 and 0. Each of these values determine the intensity of each of the three colours. Many equations are known for converting RGB to CMYK, for example. An alternative conversion method is described with reference to Figure 2.

Step 3: Account for White

However, in the prior art, white has never been accounted for with a CMYK system, as it assumes that white is the printing medium, the base paint or surface. For the invention of the present system to work effectively, it is necessary to convert an RGB vector input into a CMYK and W output (CMYKW). Using the program of the present invention, which can be found in Appendix A, the system controller 22 (of Figure 3-7) of the present invention can calculate CMYKW ratios for any inputted RGB vector, as seen in the above example. An alternative method is described with reference to Figure 2.

Step 4 : Determine the volume and finish of paint required

Many chemical and/or powder elements are also used to comprise a single sample of a particular type and finish of paint. For example, waterborne paints most often use acrylic emulsion polymers as binders. Solvent based resins come in a very wide range of types. Solvents are also used that act as a 'carrier' for the pigments and resins - the solvent may be organic (such as Mineral Turps) or may be water. Various additives are also used to enhance certain properties such as ease of brushing, mould resistance, scuff resistance, and drying time. Dependent on the required volume and finish of paint, the required volume of materials such binders, solvents and additives etc need to be calculated in precise quantities.

Step 5: Output values to a colour production machine

The output thus may then be utilised to deploy the resulting values using a system controller 22 of Figures 3-7 and onto a valve, or motor control means 44a, 44b, attached to each reservoir 5a, as shown in Figures 3-7 to dispense the required amounts of each element required. They can either be calculated by a controller within the autonomous ground deposition machine, in the cloud, or via user input, as shall be herein described.

End of Process

However, it should be noted that when doing colour conversions, it may be physically impossible to create certain colours present in different colour spaces. For example, the sRGB colour space is the standard RGB (red, green, blue) colour space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission (IEC) as IEC 61966-2-1:1999. sRGB is also usually the assumed colour space for images that are neither tagged for colour space, nor have an embedded colour profile. The sRGB colour space is quite restrictive and comprises fewer colour variations than the RGB space, for example. When compared to CMYK, the RGB model is far better as it has a wider colour spectrum. The RGB spectrum includes fluorescent greens and blues. In the CMYK system, fluorescent colours are difficult to reproduce accurately. This results in a mismatch between RGB colours and CMYK colours. So, when certain colours are converted, some may not be accurately reproduced. This inaccuracy is considered later, as described with reference to the method of Figure 8.

In Figure 9, there is shown a method of finding the wavelengths of a paint, and the mix they will produce for a given surface, according to a second embodiment of the present invention. To effectively mix paints, far more so than with inks, it is very important to consider how the spectral reflectance of paints will be transmitted to the eye as the subtractive nature of paint mixing and that the high opacity can lead to the darkening of mixed paints, or variations, on a particular surface. To counteract this, a process has been created for more accurate mixing of paints for a given surface.

Process Start:

51 - Obtain input colour reflectance values. The input colour reflectance values may either be directly obtained from a scan of a colour using a spectrophotometer scanner as known in the art or may be obtained by a user inputting the colour, or colours, they want using an image file (such as a .png or .jpg file), or by using a Pantone reference, RGB colour reference, or a HEX number, for example. In the latter case, the user input colour references need to be converted to reflectance values and so Step 2 following needs to be used.

52 - Obtain Reflectance values of input colours (if required). Using the LaGrangian formulation and Newton's method, the reflectance values of various colour values can be obtained. Whether by directly using a handheld scanner in Step 1, or by following both steps 1 & 2, the result needed before Step 3 is a 36x1 array of reflectance values of the input colour in the 380nm-730nm wavelength range.

S3. Obtain the nearest mix ratio of paints loaded into the machine. This would be implemented using a 'look up' table of the reflectance values of the colourants loaded into the autonomous ground deposition machine, the ratios needed for each RGB colour, and would be in the form of a 36x1 array for each colourant. A lookup can then be performed to find the nearest mix ratio of paints loaded into the autonomous ground deposition machine to result in the requested colour.

S4. Find base wavelengths/reflectance values. For the colour input, the ratios of each mix is required and thus the reflectance values of those base colours. For example, for a specific output colour if you need the below sub colours in the following ratios:

R : 1 Yellow : 2 Blue : 4 Total = 1+2+4 = 7

Then the resulting reflectance wavelength calculation would look like this:

RED[i] ^1/7 YELLOW[i]^2/7 BLUE[i]^4/7

This results in a new set of arrays forthe ratios of colours required to make the output colour.

S5. Create the final reflectance value of the output colour. The above ratio calculation is then applied to each reflectance element in the 36x1 array for each sub colour, resulting in a combined reflectance curve for the resulting colour. For example, for the above example the following array would be produced:

RED[i] ^1/7 YELLOW[i]^2/7 BLUE[i]^4/7

REDfii] ^1/7 YELLOW[ii]^2/7 BLUE[ii]^4/7

RED[iii] ^1/7 YELLOW[iii]^2/7 BLUE[iii]^4/7

RED[iv] ^1/7 YELLOW[iv]^2/7 BLUE[iv]^4/7 and so on

S6. Convert the Total Reflectance Array to a Linear RGB colour space. This step multiplies the output of Step 5 (the combined reflectance curve array) with a T Matrix (a Light Scattering Matrix, as known in the art), in order to result in a Linear RGB colour space output. S7. Perform a Gamma Correction to the resulting Liner RGB. This step corrects for any brightness adjustments needed.

S8. Convert Linear RGB to sRGB (or whatever is needed to display the output colour to the user). Certain user displays required certain colour spaces as an input to be able to display colour, so this step would be needed to be modified for the specific implementation.

End of Process

Due to the possible limitations of the colourants held in the autonomous ground deposition machine, that in they might not be able to be mixed in any way that could form the precise input colour requested. Thus, the colour calculated in step 5 might be a "nearest colour" or "approximate colour". Thus this "nearest colour" or "approximate colour" could then be displayed to the user to ensure the user is happy with the "nearest colour" or "approximate colour". A user of the autonomous ground deposition machine could then accept or reject the print and/or deposition.

Figure 10 is a flow diagram illustrating an output verification method, according to an embodiment of the present invention. There is shown the following method steps:

Method:

51. Obtain the required input colour values, type and volume of paint required

52. Transform to the nearest output colour value (if required) and display the result to a user. This step could use the methods as described in Figures 1, or 2 of the present invention, or any other suitable colour transformation method as known in the art.

53. Check with the user if they want to proceed, if YES, continue with the following steps. If NO, finish the process.

54. Calculate the required amounts of each colourant and/or whether dilution, solvents, binders or other suitable base materials are required for the specific paint application as input in Step SI.

55. Place (or mechanically move) a catch tank under output nozzles 56. Run the deposition program to dispense the required amounts of each material, according to the embodiments described in Figures 3 to 6 incl.

57. Mix outputted paint using embodiments as described with reference to any of figures 3 to 6 inclusive (if necessary - optional step)

58. Scan the paint mixture produced using an optical colour scanner as known in the art.

59. Re-adjust the mix, based on user inputted adjustments (if necessary - optional step) S10. Re-run Steps S3 to S7

End of method

Thus, in use, a user can input a hex value into the autonomous deposition machine for a paint colour that is required, or via another method, such as uploading an image or scanning a colour, for example.

In operation, the depositing and mixing systems of the present invention may house two, three, four or more flexible bags, or colourant cartridges, containing material for dispensing and/or mixing, the material for dispensing contained within each flexible bag being an ink or paint selected from a cyan, magenta, yellow, black, white, green, blue or red colour. Other colour space colourants can be used. The colourant materials can be powder paints, inks, concentrated paints or inks, or any other formulation of colourant materials. The flexible bags may be housed in a substantially rigid frame or using other reservoir means and would be adapted for the colourant being mixed. The hoses, valves and mixing solutions, such as solvents, binders, stabilisers or water also being chosen for the specific application.

It will be clear to one skilled in the art that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present technique.

The robots, systems, and methods described herein can be used to deposit material on multiple different substrates, surfaces, orthe ground. For example, these could be, grass, turf, AstroTurf, artificial turf, synthetic turf, plastic turf, concrete, polished concrete, tarmac or tarmacadam ground surfaces, dirt, gravel, wood chip, carpeting, rubber, roads, asphalt, brick. sand, beaches, mud, clay wood, decking, tiling, stone, rock and rock formations of varying types of rock or stone, snow, ice, ice rinks, artificial snow, polymer surfaces such as polyurethane, plastic, glass and leather.

The robots, systems, and methods described herein can be adapted for use with different surfaces, such as sports (e.g. football, cricket, racing, rugby, hockey, ice hockey, skiing, shooting) pitches, ski slopes, dry ski slopes, race courses, gymnasiums, indoor sports venues and running tracks.

In further exemplary embodiments, the robots, systems, and methods described herein may be used for printing or painting on a substrate or on the ground. This can be to print or paint, with inks or paint, logos, information, advertising or messages on the ground. When large images are printed, they are printed with adjacent dots or pixels so that when viewed from above or at a suitable distance from afar (e.g. from the stand in a stadium or from a television view) the images are easily determined. Print instructions can be determined so that when an image, e.g. a logo is printed, the print is visible from a stadium stand or by a viewer watching an event at home on television. The robots, systems, and methods described herein offer an improvement to printing methods for advertising purposes. Brand logos, slogans, pictures etc. can be printed to advertise a brand logo, image or message. These can be printed more efficiently, quickly and with a higher degree of accuracy than the methods and printers of the prior art.

Those skilled in the art will appreciate that while the foregoing has described what is considered to be the best mode and where appropriate other modes of performing present techniques, the present techniques should not be limited to the specific configurations and methods disclosed in this description of the preferred embodiment. Those skilled in the art will recognise that present techniques have a broad range of applications and that the embodiments may take a wide range of modifications without departing from any inventive concept as defined in the appended claims.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practising 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.

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.

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.

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.

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.

Claims

CLAIMS:

1. Apparatus suitable for use in an autonomous or semi-autonomous ground printing machine, the apparatus comprising: a. a first receptacle suitable for containing a first colourant substance, the first receptacle fluidly connected to a first dispenser; b. a second receptacle suitable for containing a second colourant substance, the second receptacle fluidly connected to a second dispenser: c. an output fluidly connected to the first and second dispensers; d. a controller unit, the controller unit able to take as an input, information about a required characteristic of a paint product; wherein the controller unit is operable to calculate the quantities of the first colourant substance and the second colourant substance required to form the paint product, and is operable to control the first and second dispensers to output, via an output, the required quantities of the first colourant substance and the second colourant substance.

2. A method of creating a paint for use in an autonomous or semi-autonomous ground printing machine, the paint creation method comprising: a. taking as an input, information about a characteristic of a paint product; b. calculating the required quantity of a first colourant substance and the required quantity of a second colourant substance to form the paint product; and c. controlling a first and second dispensing means to output, via an output, the required quantity of the first colourant substance and the required quantity of the second colourant substance to form the paint product; d. wherein in operation the paint product is used in a ground printing application.

3. An autonomous or semi-autonomous ground printing machine, comprising: a. navigation means; b. locomotion means; c. paint deposition apparatus; d. a first receptacle suitable for containing a first colourant substance, the first receptacle fluidly connected to a first dispenser; e. a second receptacle suitable for containing a second colourant substance, the second receptacle fluidly connected to a second dispenser; an output fluidly connected to the first and second dispensers; and f. a controller unit, the controller unit able to take as an input, information about a required characteristic of a paint product; wherein the controller unit is operable to calculate the quantities of the first colourant substance and the second colourant substance required to form the paint product, and is operable to control the first and second dispensers to output the required quantities of the first colourant substance and the second colourant substance, via the output to the paint deposition arrangement, A method or apparatus according to any preceding claim wherein both the first and second colourant substances comprise a paint base. A method or apparatus according to any preceding claim further comprising an internal chamber, wherein the internal chamber is fluidly connected between the first and second dispensers and the output. A method or apparatus according to claim 5, wherein the internal chamber is fluidly sealed. A method or apparatus according to any preceding claim, wherein the dispensing means comprises a solenoid, hydraulic pump and/or actuator valve. A method or apparatus according to any preceding claim wherein the controller can further control the timing of the first and second dispensers to create a mix of the first colourant substance and the second colourant substance. A method or apparatus according to any preceding claim wherein injected air is used to create a mix of the first colourant substance and the second colourant substance. A method or apparatus according to any preceding claim further comprising a mechanical mixer unit. A method or apparatus according to any preceding claim wherein the first and/or second receptacles comprise a flexible bag, the flexible bag provided with an airtight valve outlet sealed to the flexible bag and wherein the flexible bag is housed within a substantially rigid frame within the autonomous or semi-autonomous dispensing machine. A method or apparatus according to any preceding claim further comprising one or more cleaning fluid supply conduits, wherein the one or more cleaning fluid supply conduits are opening in the one or more dispenser heads at a cleaning fluid inlet in the internal chamber. A method or apparatus according to claim 1, 2 or 3, further comprising a choice of multiple paint products and entry via an input. A method or apparatus according to any preceding claim wherein the characteristic comprises one or more of finish, viscosity, particle size, solubility, luminosity, colour, and/or quantity. A method or apparatus according to any preceding claim wherein either the first colourant substance and/or the second colourant substance is one or more of a paint, a paint concentrate, an ink, an ink concentrate, a pigment, a coloured material, a paint powder.