WO2006060854A1

WO2006060854A1 - Robotic land transporter

Info

Publication number: WO2006060854A1
Application number: PCT/AU2005/001841
Authority: WO
Inventors: Ronald Lewis Lambert; Jeremy Duncan Lambert
Original assignee: Ronald Lewis Lambert; Jeremy Duncan Lambert
Priority date: 2004-12-07
Filing date: 2005-12-07
Publication date: 2006-06-15

Abstract

This invention relates to a robotic transporter (2) for supporting and moving over land functional apparatus (3) for operation thereof, as well as a land machine (1 ) incorporating the transporter (2). The robotic land transporter (2) includes a frame (4) for supporting functional apparatus (3) for operation; ground engaging means (10) on the frame (4) for permitting multi-axis movement of the transporter (2) over ground; and control means (6) operatively connected to the ground engaging means (10) for operating the ground engaging means (10) so as to cause the transporter (2) to controllably move over the ground. In one exemplary application, the transporter (2) is used to support and movement of irrigation apparatus (3) for spray irrigation of broad acre fields and crops.

Description

ROBOTIC LAND TRANSPORTER

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a robotic transporter for supporting and moving over land functional apparatus for operation thereof, as well as a land machine incorporating the transporter. The transporter is applicable to the agricultural and horticultural industries where the apparatus operates to work or treat field ground or crops over which the transporter moves. One example application is the support and movement of irrigation apparatus for spray irrigation of broad acre fields and crops.

It will be convenient to hereinafter describe the invention in relation to that exemplary application, although it is to be appreciated that the invention is not limited thereto. For example, the transporter may also be applicable in the mining, secondary, commercial including container and cargo handling, and recreational industries, as well as military applications where apparatus is required to be supported and moved over a ground area during a variety of functional operations.

Description of the Prior Art

The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

Conventional irrigation apparatus of a fixed or relocatable construction are unsuitable for irrigating large irregular shaped surface areas. In that regard, the installation of fixed sprinkler systems in a broad acre environment is costly and difficult to maintain. Use of relocatable sprinklers is inefficient and labour intensive. In an effort to address these problems, travelling irrigators have been developed which are capable of travelling across large areas in a simple path whilst irrigating the ground or crops. For instance, soft hose and hard hose irrigators travel in a simple irrigation path proceeding in a straight line from a starting position to a finishing position. Although these types of irrigators are relatively economical to establish and operate, they require constant relocation from the finishing point of one irrigation path to the starting position of another, resulting in labour intensive operation. These systems are only capable of irrigating a portion of a field without manual intervention to reset their irrigation path.

Conversely, centre pivot irrigation systems provide essentially labour free irrigation. The centre pivot is a self-propelled system that rotates around a central pivot point irrigating a substantially circular area. The amount of water applied in each irrigation cycle or rotation is determined by the speed of rotation. This speed is predetermined by the operator in accordance with the intensity of irrigation required in a particular area. Since the area irrigated by a centre pivot is substantially circular, in square, rectangular or irregularly shaped field, a significant portion of the field will remain unirrigated. Moreover, centre pivot irrigation systems are generally costly to procure and install. Whilst little manual intervention is required during operation of the irrigation cycle, translocation of centre pivot systems from field to field is labour intensive.

Linear move systems are comparable to centre pivot systems in construction, but rather than rotating around a central pivot point, the entire system moves laterally across the field. Linear move systems are supplied with water from a ditch that extends the length of the field or from a large hose connected to a water supply that the system drags along as it travels through the field. These systems are best suited to fields with a minimum amount of slope (0-6 percent) and are primarily adapted for use on fields that are substantially square or rectangular in shape. The systems supplied by hose have substantial labour requirements due to the need to shift the water supply hose to new supply locations to provide sufficient coverage. An object of the present invention is to overcome, alleviate or minimise one or more of the problems in the prior art.

SUMMARY OF THE INVENTION

According to one broad aspect of the present invention, there is provided a robotic land transporter including: a frame for supporting functional apparatus for operation; ground engaging means on the frame for permitting multi-axis movement of the transporter over ground; and control means operatively connected to the ground engaging means for operating the ground engaging means so as to cause the transporter to controllably move over the ground.

According to a further broad aspect of the present invention, there is provided a machine including: the above transporter; and, functional apparatus supported on the transporter for operation thereof.

This invention is described herein with reference to the transporter in a normal use orientation on a horizontally extending ground area, and terms such as "upper" and "lower" should be construed in the light of that orientation. However, it is to be appreciated that other orientations may be equally possible and that consequential changes in terms such those above may be required in the light of those other orientations for a proper and complete understanding of the invention.

Directional flexibility for movement of the present invention is provided by the ground engaging means providing multi-axis movement of the transporter over ground. In at least one embodiment of the invention, the ground engaging means includes a plurality of ground engaging assemblies. The ground engaging assemblies are preferably operable to move the transporter along two different axes and compilations thereof. In the exemplary application, the axes extend parallel to the ground over which the transporter moves, and are mutually perpendicular. It is preferable that the assemblies are operable to move the transporter along the axes in either direction.

In at least one preferred embodiment of the invention, the ground engaging means enables the transporter to move without altering its general attitude or orientation. Thus, as the transporter moves in different directions and changes directions, the transporter generally and the frame and apparatus supported thereon in particular maintains a constant attitude or orientation. This permits the apparatus to face in the same direction regardless of the direction of travel of the transporter.

In another embodiment of the invention, the ground engaging means enables the transporter to move along a path in a manner in which its general attitude or orientation is constantly changing. Thus, for example, in one embodiment of the invention, the transporter spins as it moves along a given path.

The ground engaging assemblies preferably provide for rolling contact with the ground in order to move the transporter. To that end, each ground engaging assembly can be in some embodiments of the invention a wheel assembly having at least one wheel rotatably mounted to the frame.

In one form, each wheel is rotatable about a horizontal axis in order to move the transporter along each axis and compilations thereof. In addition, in this form, each wheel is pivotable about a vertical axis in order to shift the wheel between movement axes or compilations thereof and thereby steer the transporter. Each wheel is pivotable through an angle at least equal to the angle between the axes, which in one preferred form is 90°. Each wheel may be pivotable through an angle of 360°. With this arrangement the wheel assemblies have a freedom- to-move which allows the transporter to maintain its general attitude or orientation during changes in the direction of travel.

In one preferred embodiment of the invention, the transporter includes four wheel assemblies, one each mounted to a respective mounting post at or adjacent respective ends of the support beams. It should be appreciated, however, that alternative wheel assembly numbers may be provided, for example two, three or six. Moreover, each wheel assembly may have more than one wheel, for example a pair of side-by-side wheels.

In one preferable embodiment of the invention, each wheel assembly includes a hub unit through which the wheel is rotatably mounted to the frame, and a steering unit through which the wheel is pivotably mounted to the frame.

Each hub unit preferably includes a stub axle and a wheel hub rotatably journaled on the axle, and to which the wheel is fixed. The stub axle defines a horizontal axis about which the wheel rotates, in this form. Such a hub unit arrangement will be well understood by those skilled in the relevant art.

Each steering unit preferably includes a unit housing, a steering shaft rotatably journaled in the housing, and a steering arm extending between the shaft and stub axle, so that rotation of the shaft about its longitudinal axis pivots the wheel so as to steer the transporter. In this form, the frame mounting posts may be incorporated into the steering unit housings. With this arrangement, the posts are tubular, and the steering shafts extend along inside the posts and are journaled therein.

In this form, the longitudinal axis of each steering shaft extends in a vertical plane that also contains the axis of the associated stub axle. Each steering shaft has opposed upper and lower ends, the lower end of each shaft being connected to the respective steering arm. That connection is preferably fixed. In this form, each steering arm extends clear about the respective wheel, between the respective steering and hub units. The steering arms are preferably rigid. Each steering arm typically has opposed end regions respectively fixed to the steering shaft and stub axle.

In at least one preferred embodiment of the invention, the control means includes drive means for operatively driving the ground engaging means for movement of the transporter. The drive means preferably operates to rotate and steer the wheel of at least one of the wheel assemblies. In this form, the drive means provides for independent rotation and steering of the wheel(s). The drive means can in some embodiments also provides for separate driving of the or each wheel and separate steering of the or each wheel. In this way, manoeuvrability of the transporter is maximised.

In one embodiment of the invention, the drive means preferably includes an output drive source connected directly or indirectly to one or more of the wheel hubs for rotation of the wheels and to one or more of the steering shafts for steering of the wheels, as the case may be. In alternative embodiments, a common and separate drive source is provided for rotating and steering the wheels. Thus, one drive source can be provided for rotating and steering the wheels, or separate drive sources can be provided for respectively rotating and steering the wheels. Moreover, one or more drive sources can be provided for each wheel assembly.

A separate drive source is preferably provided for rotating each wheel. Thus, in one particular embodiment of the invention, four drive sources are provided, one each associated with a respective wheel assembly. In an alternative embodiment of the invention, two drive sources are provided, one each associated with one of the wheel assemblies located adjacent a respective support beam. The remaining two wheel assemblies are typically undriven although, of course their wheels rotate with movement of the transporter.

In a preferred embodiment of the invention, a separate drive source is provided for steering each wheel. Thus, in one particular form of the invention, four drive sources are provided, one each associated with a respective wheel assembly. In an alternative form, two drive sources are provided, one each associated with one of the wheel assemblies located adjacent a respective support beam. In this alternative form, the remaining two wheel assemblies slave steer in accordance with movement of the transporter.

In a preferred embodiment of the invention, each drive source includes a drive motor. Each motor is typically a rotary output motor with an output shaft connected directly or indirectly to the wheel hub. Indirect connection is through a drive transmission including appropriate drive gear, drive chain, drive shaft and/or other transmission and translation arrangements, well known to those skilled in the relevant art.

The drive motors operate through any suitable power source, including hydraulic, pneumatic and electrical, supplied either on board or remote from the transporter. In one particular form, the drive motors are electrically powered from a generator, such as a diesel powered, three phase, 415 volt, 10 kva generator, mounted on the frame.

The control means enables the transported to controllably move over the ground. It is therefore preferable that the control means also includes guidance means connected to the drive means and responsive to predetermined instructions to selectively operate the drive means and thereby move the transporter along a path. The transporter can therefore navigate through a predetermined path over the ground.

The guidance means is preferably programmed or programmable to navigate the transporter along a complex path between pre-determined start and finish points. The guidance means is programmed or programmable in accordance with the location of those start and finish points and the complex path to be traversed by the transporter during movement thereof, in this form.

In one preferred embodiment of the invention, the complex path typically includes at least two path sections angled with respect to one another. That complex path may be further defined by a plurality of predefined way points. With this arrangement, the guidance means is programmed or programmable to guide the transporter from each predetermined way point to the next. Movement of the transporter is typically in one or more straight lines connecting the two way points. As will become apparent hereinafter, in the exemplary application of the invention as an irrigation machine, the start and/or finish point(s) and/or one or more way points may be water source locations for the irrigation apparatus. In one preferred embodiment of the invention, at least part of the complex path is defined by a first point, a second point and third point, the first point and second point lying on a straight lines; and, the first and third point lying on a second straight line, the first straight line being angled with respect to the second straight line. With this arrangement, the guidance means is operational to move the transporter from the first point to the second point and back to the first point before moving the transporter towards the third point. However, the complex path may be defined by any suitable number of way points required to provide efficient and effective movement of the transporter over the area or operation of the apparatus.

The ability to navigate a complex path independently of a human operator enables the transporter to perform movement cycles in regular or irregular shaped areas in accordance with a programmed path. That path may include multiple starting and stopping points, and require the transporter to change direction of movement at pre-determined way points. The guidance means may also enable the transporter to perform a double pass over a particular section of the complex path which may involve retracing the original path of travel in a reverse direction.

The guidance means may be directed via an external user input which may be transmitted to the transporter via remote control or similar suitable means in response to any change in conditions which may require the predetermined transporter path to be altered. In one preferred embodiment, the guidance means includes any suitable automatic pilot system having integrated automatic control, guidance and positioning systems, which is capable of directing the transporter along the predetermined path. In one form, the guidance means operates based on a global positioning system. In alternative forms, the guidance system may rely on other means, including above ground cabling, below ground cabling, guide rails or tracks above and/or below ground, radio signals or furrow construction.

The transporter frame can be of any suitable construction having regard to the intended application of the transporter. In an exemplary embodiment, the frame is of rigid, generally skeletal construction. In one form, that frame includes support members defining a platform on or from which the apparatus is supported. In that form, the frame also includes mounting members to which the ground engaging members are mounted.

In one preferred form, the frame includes support beams defining the platform. A pair of beams may extend in parallel spaced apart relationship for carriage of the functional apparatus therebetween. Those support beams extend in a plane parallel to the ground over which the transporter moves, so as to define a typically horizontal platform, in this form.

Preferably, the frame also includes mounting posts depending from the support beams, and to which the ground engaging means are mounted. At least one post extends from each beam, in this form. In one particular form, a pair of posts extend from each beam, one each at or adjacent a respective end thereof. Those posts extend perpendicularly from the beams and thus typically extend vertically.

As previously indicated, the transporter can support functional apparatus operative to work or treat a ground area over which the transporter moves. That functional apparatus will vary depending on the machine application. In the exemplary application, the apparatus is used for irrigating fields and crops. In that application, the transporter will support an irrigation apparatus for applying irrigation water from a water source to the fields and crops.

In one preferred embodiment of the invention, the irrigation apparatus includes a supply hose connectable to a water source, and at least one water dispenser connected to the hose for dispensing water delivered thereto. In this form, the water source is located remote from the apparatus, such as at a water hydrant, to which the hose is selectively connectable, the hose in use extending from the hydrant to the dispenser on the transporter frame for supplying irrigation water thereto during apparatus use. In one preferred form, the water dispenser sprays the water therefrom. To that end, the dispenser includes one or more spray nozzles. The nozzles may be of any suitable construction well known to those skilled in the relevant art. In alternative forms, a single "gun" nozzle, a single or multi span arm with a plurality of spray nozzles, and a telescopic boom with a plurality of spray nozzles, may be provided.

In at least one preferred embodiment of the invention, the irrigation apparatus also includes a hose storage device for storing, deploying and retrieving the hose. That device is mounted on the transporter frame, in this form. With this device, during use of the apparatus, sufficient hose length can be deployed so as to extend to the water hydrant for supply of water to the dispenser, with any additional hose length remaining stored on the device. The entire hose can be stored on the device when the apparatus is not in use.

The hose storage device preferably includes a storage reel mounted on the transporter frame for rotation about an axis in order to deploy and retrieve the hose. In one form, the storage device includes a support shaft on which the reel is rotatably mounted, that shaft defining the reel rotation axis. In this form, the support shaft extends between the support beams of the frame. The shaft extends perpendicularly between those beams, in one form.

In at least one preferred embodiment of the invention, the hose storage device includes a guiding means for guiding the hose onto and/or from the reel. In one form, the guiding means guides the hose onto the reel in a centre region of the reel during retrieval. That arrangement minimises damage to the hose and also reduces the likelihood of movement of the transporter being interrupted by the deployed hose. Upon hose retrieval, the guiding of the hose onto the reel at a centre region reduces tangling of the hose onto the reel, which may otherwise hinder subsequent deployment and interrupt movement of the transporter.

In at least one preferred embodiment of the invention, the hose storage device includes tensioning means for maintaining a controlled tension in the deployed hose length extending between the water hydrant and reel as the hose is deployed from or retrieved onto the reel. In particular, in this form, that tensioning means provides for deployment of the stored hose as the transporter moves away from the water source and for retraction of the deployed hose length as the transporter moves toward the water source. That tensioning means reduces tangling of the hose on the reel whilst allowing deployment as necessary during movement of the transporter.

The tensioning means preferably includes a winding motor for rotating the reel so as to progressively deploy and retrieve the hose as required during transporter movement. That winding motor is operated by the guidance means, in this form. In one form, the winding motor is powered by the same power source as the drive motors so, in one particular form, is an electrically operated rotary winding motor with an output shaft connected directly or indirectly to the hose reel. Indirect connection may be through a drive transmission including appropriate drive gear, drive chain, drive shaft and/or other transmission and translation arrangements, well known to those skilled in the relevant art.

As previously indicated, in the exemplary application of the transporter, the start and/or finish point(s) and/or one or more way points defining the complex path may be represented by water source locations such as water hydrants for the irrigation apparatus. Thus, in operation the transporter will be programmed or programmable to move between those water source locations. Where that occurs the irrigation apparatus in at least one preferred form includes coupling means to automatically connect the hose to the or each water hydrant for supply of water to the dispenser, and to automatically disconnect the hose therefrom upon completion of an irrigation cycle. In this form, the coupling means is associated with the hose and water hydrant(s). Moreover, the coupling means is operated by the guidance means so as to achieve connection and disconnection between the hose and hydrant(s).

DESCRIPTION OF THE DRAWINGS

The following description refers to a preferred embodiment of an irrigation machine incorporating the transporter of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the machine and transporter are illustrated in that preferred embodiment. It is to be understood that the machine and transporter are not limited to the preferred embodiment as hereinafter described and as illustrated in the drawings.

In the drawings:

Fig. 1 is a schematic illustration of one example of a complex path in an irregularly shaped area which can be automatically irrigated by an irrigation machine incorporating the present invention;

Fig. 2 is a schematic top view of an irrigation machine incorporating one preferred embodiment of the present invention;

Fig. 3 is a schematic side view of the irrigation machine of Fig. 2;

Fig. 4 is a schematic end view of the irrigation machine of Fig. 2; and

Fig. 5 is a schematic diagram of the control system of one preferred embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring initially to Fig. 1 , there is generally shown a simplified schematic view of an example complex path P in an irregular shaped area A which can be automatically irrigated in accordance with the present invention.

The complex path P includes two or more path lines L_n which are angled with respect to one another. The angle α may be any angle in the range of 0-360°. The complex path P is defined by a plurality of predetermined way points P_n. At least part of the complex path P is defined by a first point Pi second point P₂ and third point P₃, the first and second points P-i, P₂ lying on a first path line Li, and the first and third points P-i, P₃ lying on a second path line L₂, wherein the first line L₁ is angled with respect to the second line L₂. One or more of the points P_n may be defined by water hydrants H.

Referring now to Figs. 2 to 4, there is generally shown an irrigation machine 1 including a transporter 2 on which is supported and carried irrigation apparatus

3. The transporter 2 includes a frame 4, ground engaging means 5 mounted on the frame 4 for permitting multi-axis travel of the apparatus over the surface of ground G, and control system 6 connected to the ground engaging means 5 for operating that means 5 so as to cause the transporter to move along complex path P. The transporter frame 4 includes two support beams 7 and four mounting posts 8 depending from the beams 7 adjacent respective ends thereof.

The ground engaging means 5 includes four wheel assemblies 9 associated one each with a respective mounting post 7. Each wheel assembly 9 includes a wheel 10 rotatable about an axis X and pivotable about an axis Y. Each wheel assembly 9 includes a hub unit 1 1 which mounts the wheel 10 to the frame 4 for rotation about axis X, and a steering unit 12 through which the wheel 10 is pivotably mounted to the frame 4 for pivotal movement about axis Y. Due to the angular freedom of the wheels 10, the transporter 2 has no defined 'front' side. In this regard, any portion of the vehicle can be the 'front' at a given time depending on the direction the wheels 10 is pivoted about axis Y and the direction the wheel 10 is rotating about axis X. For example, in some embodiments one of the sides of the transporter 2 could be orientated to form the front of the transporter 2. Equally, a corner of the transporter 2 could be orientated to be the front of the transporter 2. This allows the transporter 2 in these embodiments, to move in any direction without changing its attitude.

In other embodiments of the invention, the transporter 2 is configured so that the attitude constantly changes during movement. For example, in one embodiment the transporter 2 spins about an axis, for example a central vertical axis as it moves along a given path. In other embodiments, the front of the transporter 2 is orientated in different and in some forms random directions as it moves along a given path. Each hub unit 1 1 includes a stub axle 13 and a wheel hub 14 rotatably journaled on the axle 13 and to which the wheel 10 is fixed.

Each steering unit 12 includes a housing 15, a steering shaft 16 journaled in the housing 15 and a steering arm 17 extending between the shaft 16 and stub axle 13. With this arrangement, rotation of the steering shaft 16 about axis Y causes steering of the transporter 2.

The control system 6 includes drive means 18 for operatively rotating and steering the wheels 10. The drive means 18 includes a series of electrical drive motors 19 (only one of which is shown) associated one each with a respective wheel 10 for rotatably driving that wheel 10, and a series of electrical steering motors 20 (only one of which is shown) associated one each with a respective wheel 10 for rotating the respective steering shaft 16 so as to steer that wheel 10. The electric motors 19, 20 are electrically powered from an on-board generator (not shown).

The control system 6 also includes guidance means 21 for independently navigating the transporter 2 along the complex path P. Any suitable guidance means 21 having integrated automatic control, guidance and positioning systems is provided. Preferably the operation of the guidance means 21 is based on a global positioning system (GPS). Alternatively, operation of the guidance means 21 can be based on systems including above ground cabling, below ground cabling, radio signals, or furrow construction. Programmable logic controller devices or the like may control the guidance means.

The guidance means 21 automatically directs the transporter 2 to a predetermined water supply location such as a water hydrant H. The machine 1 can be operated using existing in field water hydrants H, making it possible to use the machine 1 in conjunction with existing infrastructure and thereby substantially reduce the costs of operating the machine 1 according to the present invention. The ability of the transporter 2 to be programmed to connect automatically to existing in field water supply hydrants H means that movement of the transporter 1 within area A will not be restricted by factors including water supply pressure.

The guidance means 21 may be directed via an external user input. External inputs may be transmitted to the transporter 2 via remote control or similar means in response to a change in conditions or obstructions which may block the pre-determined irrigation path.

Fig. 5 shows a schematic diagram of the data flows for one preferred embodiment of the control system 6 of the present invention. The illustrated control system 6 is a computer operated system which includes guidance system 21 in the form of a computer system 30 running an operating system and specific application programs which controls electric motors 32, 34 and supporting electronic componentary 36, 38, 39. In addition, various sensors provide inputs to the computer control system 6. In the illustrated system 6 the sensors include:

• Mechanical sensors including rotary encoders 40, micro-switches 42 and hall-effect sensors 44; and • Navigational sensors including Real Time Kinematic (RTK) 46, Global Positioning System (GPS) 48 and an electronic compass 49.

It is understood that various other similar or equivalent sensors or optional devices 50 could be utilised to provide input to the computer control system 6, and that the control system 6 of the present invention could include all such sensors. Furthermore, it can be appreciated that two or more of the navigational sensors could be combined into a single unit. For example, in the illustrated embodiment, the Real Time Kinematic (RTK) 46, Global Positioning System (GPS) 48 could be combined into a single unit when included in the control system 6 of the present invention.

The actions of the control system 6 and therefore of the machine 1 are governed by the combination of routes and tasks programmed into the system by the user/operator and the inputs received from the various sensors/devices into the computer system 30. Using this input, the control system 6 outputs commands to various devices such as electric motors 32, 34 and supporting electronic componentary in the irrigation machine 1.

To operate the irrigation machine 1 using the control system 6, the operator either enters a series of routes (made up of a series of waypoints P_n as for example is shown in figure 1 ) into the computer system 30 or calls up one of several previously saved routes stored in the computer system 30. The control system 6 can be programmed to have an action of the machine 1 associated with each waypoint P_n. These actions may include one or more of the following:

• changing speed of transporter 2;

• changing direction of travel of transporter 2;

• connecting the irrigation machine 1 with a water hydrant H; • disconnecting the irrigation machine 1 with a water hydrant H;

• lowering or raising tillage/seeding equipment;

• changing the 'front' of the transporter 2 (without changing the attitude); or

• changing mode from 'travel' mode where the transporter 2 is primarily moving to 'work' mode in which the irrigation machine the functional apparatus such as an a water dispenser 26 is operated;

In operation, the computer system 30 calculates the theoretical path that the transporter 2 should be travelling and compares this with the constant positional updates being received from the GPS 48. Deviations from the desired route are corrected by the computer system 30 sending commands to the electrical drive motors 32, 34 associated one each with a respective wheel 10 which change the angle of the wheels 10 relative to the frame 4 of the transporter 2 thereby steering the transporter 2 back to the predetermined route. The angle of the wheels 10 is constantly monitored by a rotary encoder 40 attached to the steering shaft 16 of each wheel 10, and is fed back to the computer system 30 via a proprietary sensor board 38.

Bearings from the electronic compass 49 constantly feed into the computer system 30 enabling the monitoring of the attitude of the transporter 2 so that yaw corrections can be made by the computer system 30 as necessary by applying differential steering angles to the wheels 10.

By individually controlling the rotational speed and angle of turn of each wheel 10, the control system 6 creates three modes of steering:

• two wheel which is the conventional mode of steering;

• four wheel in which each wheel assumes the same angle; and

• articulated in which the 'front' wheels and 'rear' wheels assume opposing angles of steering.

Differential rates of steering (e.g. inside wheels having more lock than outside wheels of a turn also known as Ackerman steering) and differential wheel 10 speeds (e.g. outer wheels turning faster than inner wheels in a turn) can also be implemented and easily adjusted through the control system 6 software. In essence, the control system 6 coupled with the directional flexibility afforded by the configuration of the transporter 2 allows for major changes in the operation of the transporter 2, through software changes without need for mechanical alterations.

The control system 6 also allows a user 52 to take manual control of the transporter 2. Manual control can be implemented through direct input into the computer system or through manipulation of a remote control device (not shown). Manual control would typically be necessary when it is required to move the irrigation machine 1 to a new paddock for use. Manual control of the transporter 2 may be in any of the three steering modes mentioned previously.

The control system 6 also monitors the health of individual subsystems such as:

• Accuracy of GPS positioning;

• Number of satellites "locked on" by the GPS 48;

• Error condition in GPS 48;

• Load on drive motors 32;

• Load on steering motors 34; • Error condition in drive 32 or steering 34 motor controllers (VSDs);

• Error condition in electronic compass 49;

• Excessive steering angles for each wheel 10;

In operation, the transporter 2 is movable in either direction on axis A. Upon pivoting the wheels 10 through an angle of 90°, by rotating the steering shafts 16, the transporter 2 can be moved in either direction along axis B. Varying the angle of rotation of the steering shafts 16 will enable movement of the transporter in either direction along axes compiled from axes A and B. That multi-axis movement can be achieved without having to reorientate or reposition the transporter 2 as a whole. Moreover, that change in axial movement can be achieved without turning of the transporter as a whole. Thus, the transporter 2 has zero turn radius capacity.

The irrigation apparatus 3 mounted on the transporter frame 4 includes a length (for example 300 metres) of hose 22 for conveying water from a water hydrant H to the transporter 2. That hose 22 is stored, deployed and retrieved by a hose storage means 23 mounted on the frame 4.

The hose storage means 23 includes a storage reel 24 mounted on the frame 4 for rotation about an axis Z for deployment and retrieval of the hose 22. The reel 24 is mounted on a support shaft or axle 25 extending between the support beams 7 for that purpose.

The irrigation apparatus 3 further includes a water dispenser 26 mounted on the transporter frame 4 and connected to the hose 22 for dispensing water delivered thereto. In this example, the dispenser 26 is in the form of a "gun" spray nozzle for directing a spray of water onto ground G over which the transporter 2 moves.

The irrigation apparatus 3 may include a hose guide 27 for guiding the hose 22 onto and/or from the storage reel 24. During retrieval, the hose guide 27 guides the hose 22 onto the reel 24 at a centre region of the reel 24. As shown in Figs. 2 and 3, the irrigation apparatus 3 also includes tensioning means 29 in the form of variable speed drive 31 coupled to the support shaft 25 via a transmission means, which in the illustrated embodiment the support shaft 25 is chain driven by a chain belt 31. The tensioning means 29 is used to maintain tension in the hose 22, as it is deployed from and retrieved onto the reel 24. In particular, the tensioning means 29 provides for deployment of a length of hose 22 from the reel 24 as the transporter 2 moves away from the water hydrant H. Similarly, the tensioning means 29 provides for retraction of a deployed length of hose 22 as the transporter 2 moves toward the hydrant H. The tensioning means 29 automatically maintains tension in that hose length between the hydrant H and reel 24 so as to prevent the hose 22 from becoming tangled and potentially damaged, or interrupting movement of the transporter 2. Further, since the tensioning means 29 provides for the deployed length of hose 22 to retract when no longer required, the transporter 2 does not need to drag that deployed hose length which otherwise may significantly effect the progress of the transporter 2 and make transporter 2 navigation more difficult, particularly over rough or undulating ground G.

The variable speed drive 31 of the tensioning means 29 is operated by the control system 6 as shown in Fig. 5. Control of the tensioning means 29 is assisted in this embodiment by a sensor which measures the tension in the hose 22. If the tension in the hose 22 is too great, the variable speed drive 31 is operated to increase the deployed length of the hose 22 to reduce the tension. If the tension in the hose 22 is below a certain set point, the variable speed drive 31 is operated wind the hose 22 in until the tension in the hose 22 meets the set point tension. Accordingly, the tensioning means 29 automatically maintains tension in the hose 22 length.

The guidance means 21 may be programmed or programmable to provide for differential irrigation over the area A to be irrigated. Differential irrigation allows for different area parts or zones to be irrigated at different rates in accordance with the requirements of each individual zone. Further, the guidance means 21 may be programmed or programmable to orientate and reorientate the water dispenser so as to direct water sprays in selected directions. In this way, for example, the machine 1 can be programmed so as to irrigate only on a selected side of the transporter 2, for example when traversing boundaries of the area A.

It is to be understood that various alterations, additions and/or modifications may be made to the transporter and machine without departing from the ambit of the present invention as defined in the claims appended hereto.

Claims

1. A robotic land transporter including: a frame for supporting functional apparatus for operation; ground engaging means on the frame for permitting multi-axis movement of the transporter over ground; and control means operatively connected to the ground engaging means for operating the ground engaging means so as to cause the transporter to controllably move over the ground.

2. A robotic land transporter according to claim 1 , in which the ground engaging means are operable to move the transporter along two different axes and compilations thereof.

3. A robotic land transporter according to claim 2, in which the two different axes extend parallel to the ground over which the transporter moves, and are mutually perpendicular.

4. A robotic land transporter according to any one of the preceding claims, in which the ground engaging means includes a plurality of ground engaging assemblies.

5. A robotic land transporter according to claim 4, in which each ground engaging assembly is a wheel assembly having at least one wheel rotatably mounted to the frame.

6. A robotic land transporter according to claim 5, in which each wheel is rotatable about a horizontal axis in order to move the transporter along each axis and compilations thereof, and each wheel is also pivotable about a vertical axis in order to shift the wheel between movement axes or compilations thereof and thereby steer the transporter.

7. A robotic land transporter according to claim 6, in which each wheel is pivotable through an angle at least equal to the angle between the horizontal and vertical axes.

8. A robotic land transporter according to any one of claims 4 to 7, in which each wheel assembly includes a hub unit through which the wheel is rotatably mounted to the frame, and a steering unit through which the wheel is pivotably mounted to the frame.

9. A robotic land transporter according to claim 8, in which each hub unit includes a stub axle and a wheel hub rotatably journaled on the axle, and to which the wheel is fixed, the stub axle defining a horizontal axis about which the wheel rotates.

10. A robotic land transporter according to claim 8 or 9, in which each steering unit includes a unit housing, a steering shaft rotatably journaled in the housing, and a steering arm extending between the shaft and stub axle, so that rotation of the shaft about its longitudinal axis pivots the wheel so as to steer the transporter.

1 1. A robotic land transporter according to any one of the preceding claims, in which the control means includes drive means for operatively driving the ground engaging means for movement of the transporter.

12. A robotic land transporter according to any one of the preceding claims, in which the ground engaging means includes a plurality of ground engaging wheel assemblies, the drive means operates to rotate and steer the wheels of at least one of the wheel assemblies.

13. A robotic land transporter according to claim 12, in which the drive means provides for independent rotation of the or each wheel and independent steering of the or each wheel.

14. A robotic land transporter according to claim 12, in which a separate drive source is provided for rotating, steering or a combination thereof of at least two different wheels.

15. A robotic land transporter according to any one of the preceding claims, in which the control means includes a guidance means connected to the drive means and responsive to predetermined instructions to selectively operate the drive means and thereby move the transporter along a path.

16. A robotic land transporter according to claim 15, in which the guidance means is programmed or programmable to navigate the transporter along a complex path between pre-determined start and finish points.

17. A robotic land transporter according to claim 15 or 16, in which the complex path may be further defined by a plurality of predefined way points such that the guidance means is programmed or programmable to guide the transporter from each predetermined way point to the next.

18. A robotic land transporter according to claim 17, in which the at least one of the start point, finish point, or one or more of the way points are water source locations for the functional apparatus.

19. A robotic land transporter according to claim 18, in which the guidance means is directed via an external user input which may be transmitted to the transporter via remote control or similar suitable means in response to any change in conditions which may require the predetermined transporter path to be altered.

20. A robotic land transporter according to any one of claims 15 to 19, in which the guidance means operates based on a global positioning system.

21. A robotic land transporter according to any one of the preceding claims, in which the functional apparatus includes an irrigation apparatus for applying irrigation water from a water source to the fields and crops, the irrigation apparatus including a supply hose connectable to a water source, and at least one water dispenser connected to the hose for dispensing water delivered thereto.

22. A robotic land transporter according to any one of the preceding claims, in which the irrigation apparatus also includes a hose storage device mounted on the transporter frame for storing, deploying and retrieving the hose.

23. A robotic land transporter according to claim 22, in which the hose storage device includes a guiding means for guiding the hose onto and/or from the reel.

24. A robotic land transporter according to claim 22 or 23, in which the hose storage device includes tensioning means for maintaining a controlled tension in the deployed hose length extending between the water hydrant and reel as the hose is deployed from or retrieved onto the reel.

25. A robotic land transporter according to claim 24, in which the tensioning means includes a winding motor operated by the guidance means for rotating the reel so as to progressively deploy and retrieve the hose as required during transporter movement.

26. A machine including: a transporter according to any one of the preceding claims; and functional apparatus supported on the transporter for operation thereof.