WO2014186822A1

WO2014186822A1 - A method of controlling a mine vehicle and a mine vehicle control system

Info

Publication number: WO2014186822A1
Application number: PCT/AU2014/000524
Authority: WO
Inventors: Florian Oppolzer; Justin YOUNG
Original assignee: Technological Resources Pty Ltd
Priority date: 2013-05-20
Filing date: 2014-05-16
Publication date: 2014-11-27

Abstract

A mine vehicle control system (10) includes a vehicle controller (14). The vehicle controller (14) is responsive to a control zone (16) defining a part of an area traversed by a mine vehicle (12). A navigation module (24) determines a position and orientation of the vehicle (12) relative to the control zone (16). The navigation module (24) communicates with the vehicle controller (14) and supplies data relating to the position of the vehicle (12) relative to the control zone (16) as the vehicle (12) automatically traverses towards the control zone (16). A processing unit (26) is responsive to the navigation module (24) to generate a datum line extending transversely to the control zone (16) for assessing the orientation of the vehicle (12) relative to the control zone (16). The processing unit (26) has at least a part configured as a decision engine (36) which causes the vehicle controller (14) to manoeuvre the vehicle (12) so that the operative component of the vehicle (12) is positioned at a destination location in the control zone (16) provided the orientation of the vehicle (12) falls within predetermined parameters.

Description

"A method of controlling a mine vehicle and a mine vehicle control system" Cross-Reference to Related Applications

[0001] The present application claims priority from Australian Provisional Patent

Application No 2013901784 filed on 20 May 2013, the contents of which are incorporated herein by reference in their entirety.

Field

[0002] This disclosure relates, generally, to controlling a mine vehicle and, more particularly, to a method of controlling a mine vehicle and to a mine vehicle control system. The disclosure has particular, but not necessarily exclusive, application in controlling a drill rig on a bench of an open cut mine.

Background

[0003] Increasingly in mining operations, vehicles on the mine site are operated autonomously. However, there are circumstances where extra safety precautions need to be taken to prevent dangerous or unsafe situations arising. In such circumstances, autonomous control of the vehicle needs to cease and the vehicle needs to be controlled, generally, in a tele-remote manner or in a completely manual manner.

[0004] When this occurs, the overall efficiency of the mining operation can be adversely affected with the resultant negative effect on the economic benefits arising from autonomous operation of the vehicles.

Summary

[0005] In a first aspect, there is provided a method of controlling a mine vehicle which includes

referencing a control zone, the control zone defining a part of an area traversed by the vehicle;

monitoring the passage of the vehicle as it automatically traverses the area towards the control zone; assessing the orientation of the vehicle relative to the control zone to ensure that an operative component of the vehicle approaches the control zone first; and

manoeuvring the mine vehicle so that at least the operative component of the vehicle is positioned in vicinity of a predetermined destination location within the control zone provided the orientation of the vehicle relative to the control zone falls within predetermined parameters.

[0006] The control zone may define a region of the area traversed by the vehicle where caution in operating the vehicle needs to be exercised and other safety precautions need to be taken. Further, the term "automatically" is to be understood, unless the context clearly indicates otherwise, as being a system decision rather than an operator decision.

[0007] The method may include monitoring the position of the vehicle in the area and the position of the vehicle relative to the control zone.

[0008] The method may include defining an outer bounding box surrounding at least an outer perimeter of the vehicle and an inner bounding box contained within the perimeter of the vehicle and surrounding at least the operative component of the vehicle. Further, the method may include defining the outer bounding box and the inner bounding box to have a buffer of a preselected size.

[0009] The method may include assessing the orientation of the vehicle when any part of the outer bounding box reaches a predetermined position relative to the control zone.

[0010] The method may include assessing the orientation of the vehicle by generating a datum line associated with, and extending transversely, from the control zone. The method may include generating a substantially rectilinear datum line.

[001 1] Further, the method may include assessing the orientation of the vehicle by monitoring a heading of the vehicle relative to the control zone. Thus, the method may include assessing the heading of the vehicle by monitoring an approach angle of the vehicle relative to the control zone.

[0012] The control zone may be defined by an edge and a spaced control zone line extending parallel to the edge and the method may include determining the orientation of the vehicle relative to the control zone line by monitoring the approach angle of the vehicle relative to the control zone line. More particularly, the method may include determining the orientation of the vehicle by monitoring the approach angle of the operative component of the vehicle relative to the control zone line.

[0013] The method may include, if the approach angle is within tolerance, manoeuvring the vehicle so that the operative component of the vehicle enters the control zone.

[0014] The method may include taking remedial action by one of (a) repositioning the vehicle automatically and (b) converting from automated control to operator-controlled control of the vehicle if the orientation of the vehicle relative to the control zone falls outside the predetermined parameters.

[0015] In a second aspect, there is provided a method of controlling a mine vehicle relative to a control zone of an area being traversed by the mine vehicle, the method including

generating a datum line associated with, and extending transversely to, the control zone;

generating a reference line extending substantially in the direction of travel of the vehicle;

determining an included angle between the datum line and the reference line at a point where the reference line and the datum line intersect; and

provided the included angle falls within a predetermined tolerance, permitting the vehicle to continue to traverse the area so that at least an operative component of the vehicle enters the control zone at a desired orientation relative to a destination location within the control zone.

[0016] The method may include generating a substantially rectilinear datum line. Similarly, the method may include generating a substantially rectilinear reference line.

[0017] The method may include at least partially defining the control zone by a control zone line extending in spaced parallel relationship relative to an edge of the control zone. The method may further include generating the datum line to extend substantially normal to the control zone line. Still further, the method may include generating the datum line between a point on the control zone line closest to the vehicle and the vehicle itself. [0018] The method may include generating the datum line between the point on the control zone line and the operative component of the vehicle. In particular, the method may include generating the datum line from the point on the control zone line to the vehicle to ensure that an orientation of the vehicle relative to the control zone is correct, i.e. that a correct part of the vehicle is approaching the control zone first. The "correct part" of the vehicle is to be understood, unless the context clearly indicates otherwise, as that part of the vehicle containing the operative component of the vehicle.

[0019] In a third aspect, there is provided a mine vehicle control system which includes a vehicle controller, the vehicle controller being responsive to a control zone defining a part of an area traversed by a mine vehicle;

a navigation module for determining a position and orientation of the vehicle relative to the control zone, the navigation module being in communication with the vehicle controller for supplying the vehicle controller with data relating to the position of the vehicle relative to the control zone as the vehicle automatically traverses the area towards the control zone; and a processing unit which is responsive to the data from the navigation module to generate a datum line associated with, and extending transversely to, the control zone for assessing the orientation of the vehicle relative to the control zone, the processing unit having at least a part configured as a decision engine which uses the datum line to ensure that an operative component of the vehicle approaches the control zone first and to cause the vehicle controller to manoeuvre the vehicle so that at least the operative component of the vehicle is positioned at a destination location in the control zone provided the orientation of the vehicle relative to the control zone falls within predetermined parameters.

[0020] The processing unit may be configured to generate the control zone and to process the data related to the vehicle, the processing unit further being operable to impart an outer bounding box about at least an outer perimeter of the vehicle and an inner bounding box contained within the perimeter of the vehicle and surrounding at least the component of the vehicle. The processing unit may be configured to define the outer bounding box and the inner bounding box to have a buffer of a preselected size.

[0021] The processing unit may be configured to assess the orientation of the vehicle relative to the control zone as soon as any portion of the outer bounding box reaches a predetermined position relative to the control zone. [0022] The processing unit may be configured to assess the orientation of the vehicle by monitoring a heading of the vehicle relative to the control zone. Further, the processing unit may be configured to assess the heading of the vehicle by monitoring an approach angle of the vehicle relative to the control zone.

[0023] The processing unit may be configured to generate a substantially rectilinear datum line extending transversely to the control zone and to monitor the approach angle of the vehicle relative to the datum line.

[0024] The control zone may be defined by an edge and a spaced control zone line extending parallel to the edge with the datum line extending substantially normal to the control zone line. More particularly, the processing unit may be configured to monitor the approach angle of the component of the vehicle relative to the datum line.

[0025] The decision engine of the processing unit may be operative, if the orientation of the vehicle relative to the control zone falls outside the predetermined parameters, to cause remedial action to be taken. More particularly, the decision engine may be operative, where remedial action is required, to do one of (a) repositioning the vehicle automatically and (b) converting from automated control to operator-controlled control of the vehicle.

[0026] The system may include operator-manipulated controls for enabling an operator to convert from automated control to operator-controlled control of the vehicle.

[0027] The disclosure extends to software that, when installed on a computer, causes the computer to perform either of the methods as described above.

[0028] The disclosure also extends to a mine vehicle which is responsive to a mine vehicle control system as described above.

[0029] The disclosure extends still further to a method of generating a control zone in an area of a mine, the method including

determining an edge of the area; and

projecting a distance in from the edge to form a line extending parallel to the edge to form a corridor defining the control zone along the edge. [0030] The method may include configuring the distance between the line and the edge. The distance between the line and the edge may be configured based on external factors such as, for example, the type of edge (e.g. a face edge or a high wall edge), hardness of a substrate of the area, the type of vehicle being controlled in the area, the operations to be carried out by the vehicle in the area, or the like.

Brief Description of Drawings

[0031 ] An embodiment of the disclosure is now described by way of example with reference to the drawings in which :-

[0032] Fig.l shows a schematic block diagram of an embodiment of a mine vehicle control system;

[0033] Fig. 2 shows a screen shot of a bench of an open cut mine on which a control zone has been generated;

[0034] Fig. 3 shows a screen shot of a mine vehicle of the bench with an outer bounding box being demarcated about the vehicle;

[0035] Fig. 4 shows a screen shot of the mine vehicle and an inner bounding box demarcated within a periphery of the vehicle;

[0036] Figs. 5 A & 5B show screen shots of impermissible approaches of the mine vehicle to a control zone requiring remedial action to be taken;

[0037] Fig. 6 shows a flow chart of steps in an embodiment of a method of controlling a mine vehicle relative to a control zone insofar as such method is applied to controlling a drill rig;

[0038] Fig. 7 shows a flow chart of steps in assessing the orientation of the mine vehicle relative to the control zone; and

[0039] Fig. 8 shows a schematic representation of determining a heading of the drill rig relative to the control zone. Detailed Description of Exemplary Embodiments

[0040] Referring initially to Fig. 1 of the drawings, reference numeral 10 generally designates a mine vehicle control system. The mine vehicle control system is intended for controlling a mine vehicle which, in the illustrated embodiment, is a drill rig 12. The system 10 includes a vehicle controller 14. The vehicle controller 14 is, in use, responsive to a control zone 16 (Fig. 2) defined in an area, more particularly, a bench 18 of a mine site to be traversed by the drill rig 12.

[0041] For ease of reference, the disclosure will be described with reference to its application in controlling a drill rig 12. However, those skilled in the art will appreciate that the control system 10 could be used in controlling other autonomous vehicles. For example, the control system 10 could be used in controlling traversal of the area by an autonomously operated blast hole charging vehicle which needs to approach particular blast holes from only one side. Also, the control system 10 could be used for controlling autonomously operated load haul dumpers (LHD) which sometimes are used to dump waste material from blasting operations over the edge of the bench 18 and which need to traverse to an edge 22 of the bench 18 to carry out such dumping operations.

[0042] Thus, in this specification, unless the context clearly indicates otherwise, the term "mine vehicle" is to be understood as a vehicle used exclusively in a mining environment and having an operative component such as a drill mast in the case of a drill rig, a tipping load bed in the case of an LHD, a bucket in the case of an excavator, a blade in the case of a bulldozer or grader, an auger of a blast hole charging vehicle, or the like. The preceding list is not intended to be exhaustive and those skilled in the art will readily appreciate that other vehicles are used exclusively in mining environments and include operative components used in mining operations or containing adaptations which render such vehicle suitable for use in a mining environment.

[0043] An operating system 20 of the drill rig control system 10 is implemented in software and comprises various software modules. The operating system 20 includes a navigation module 24 for determining the position and orientation of the drill rig 12 on the bench 18 and which monitors progress of the drill rig 12 as it traverses or trams on the bench 18.

[0044] The operating system 20 of the drill rig control system 10 also includes a processing unit or processor 26. In the described embodiment, the processor 26 forms part of the operating system 20 but it will be appreciated that the processor 26 could be a stand-alone processor or, in some embodiments, could be mounted within the vehicle controller 14 of the drill rig 12.

[0045] The navigation module 24 receives data from various input devices and/or sensors for determining the location of the drill rig 12 on the bench 18 with accuracy. The drill rig 12 includes a GPS unit 28 which, for example, is a high precision (HPGPS) unit, one or more video cameras 30 and other positioning determining sensors such as wheel encoders, laser scanners, or the like. Data from the drill rig 12 mounted equipment are transmitted via a communications link 32 to the navigation module 24 of the drill rig operating system 20. The navigation module 24 thus determines the location of the drill rig 18 of the drill rig 12 on the bench 18 and provides the location information to the processor 26.

[0046] The data from the navigation module 24 are also provided to a tramming control module 34 which operates under the control of the processor 26. The tramming control module 34 is used for automated tramming of the drill rig 12 using information provided by the navigation module 24 and effects navigational control of the drill rig 12 via the communications link 32.

[0047] The processor 26 is further configured to operate as a decision engine 36. The decision engine 36 is illustrated, for the sake of clarity, as a separate module but, in use, the decision engine 36 is implemented as a software module of the processor 26. The decision engine 36 monitors the orientation of the drill rig 12 on the bench 18, particularly when the drill rig 12 approaches the control zone 16, and assesses whether the drill rig 12 is to continue tramming into the control zone 16 or if remedial action is to be initiated, whether under continued automated operation of the drill rig 12 or ceasing automated control of the drill rig and switching over to manual, operator-controlled control of the drill rig 12.

[0048] The operating system 20 also includes a safety module 38. The safety module 38 is responsible for monitoring the status of the drill rig 12, detecting possible collisions and for implementing obstacle avoidance manoeuvres and taking other preventative action to inhibit emergency situations arising. [0049] The operating system 20 still further includes a manual control module 40. The manual control module 40 enables an operator to override autonomous operation of the drill rig 12 and to assume manual control of the drill rig 12. The manual control can either be effected from a cab 42 of the drill rig 12 or via remote control.

[0050] The operating system 20 includes a user interface 44. The user interface 44 includes a display 46 on which the bench 18 is displayed and the position of the drill rig 12 on the bench 18. Still further, the control zone 16 is displayed on the bench 18.

[0051] The user interface 44 has various inputting devices such as a keyboard 48, pointing devices (not shown) or touch screen facilities on the display 46. The user interface 44 receives inputs from the processor 26 of the operating system 20 and from an operator of the operating system 20. Instructions and data from the operating system 20 are communicated via a communications link 50 wirelessly to the controller 14 of the drill rig 12.

[0052] Referring again to Fig. 1 of the drawings, the drill rig 12 has a drill mast 52 mounting a drill string 54. The drill mast 52 and the cab 42 are mounted on a platform 60. The drill mast 52 and the cab 42 are mounted proximate a first end 56 of the platform 60 of the drill rig 12 with the platform 60 having an opposed end 58. For ease of explanation, the end 56 of the drill rig 12 is referred to as the "drill string-end" of the drill rig 12. It will be appreciated that, for a fully autonomous or remotely controlled drill rig 12, the cab 42 may be omitted.

[0053] The platform 60 of the drill rig 12 is supported on a pair of spaced tracks 62. The drill rig 12 includes a pair of jacks 64 associated with each track 62, each jack 64 being mounted in spaced relationship relative to an end of its associated track 62. The jacks 64 are used to raise the tracks 62 off a substrate of the bench 18 when drilling is being effected by the drill rig 12

[0054] The disclosure is particularly applicable to facilitating autonomous tramming of the drill rig 12 to areas which mandate caution in operating the vehicle and/or where other safety precautions need to be taken. As will be appreciated, on a bench 18, a face edge 22 constitutes a dangerous zone as the edge 22 may not be clearly defined or may not be structurally sound and could result in the drill 12 tramming over the edge 22. The bench 18 may also be bounded on at least one side by a high wall as illustrated at 66 in Fig. 3 of the drawings. It is required that the drill rig 12 be trammed in such a manner as to prevent colliding with the high wall 66.

[0055] For ease of explanation, the disclosure will be described with reference to the operation of the drill rig 12 relative the face edge 22 of the bench 18 along which the control zone 16, which will be referred to as a face zone 16, is to be established. The face zone 16 is established by projecting a control zone line, or face zone line, 68 (Fig. 2) inwardly from the edge 22, the line 68 extending parallel to the edge 22 to form a corridor defining the face zone 16. This is shown at step 70 in Fig. 6 of the drawings. At step 71 , all hole locations 72 within the face zone 16 to be drilled by the drill rig 12 are identified and are designated as face hole locations. The face data comprising the layout of the face zone 16 and the face hole locations 72 are input by the processor 26 into the vehicle controller 14 of the drill rig 12 as shown at step 74.

[0056] Using the navigation module 24 of the operating system 20 of the drill rig control system 10, the approach of the drill rig 12 to the face zone 16 is monitored as shown at step 76.

[0057] For the purposes of determining safe tramming of the drill rig 12 on the bench 18, the processor 26 defines an outer bounding box 78 (Fig. 3). The outer bounding box 78 encompasses the outer periphery of the drill rig 12, including its cradle, with a buffer of approximately 0.5 metres.

[0058] Further, as shown in Fig. 4 of the drawings, the processor 26 also defines an inner bounding box 80. The inner bounding box 80 is contained within the periphery of the drill rig 12 and encompasses the tracks 62, the drill string 54 and the jacks 64 of the drill rig 12. The inner bounding box 80 also includes a buffer of approximately 0.5 metres. These bounding boxes 78 and 80 are used by the processor 26, in conjunction with details of the face zone 16 and/or, where applicable, a high wall zone (not shown), to determine a safe working area for the drill rig 12 on the bench 18. The bounding boxes 78 and 80 are also used to ensure safe tramming of the drill rig 12 into the face zone 16 to enable blast holes to be drilled at each of the face hole locations 72. [0059] Accordingly, the processor 26 monitors the approach of the drill rig 12 to the face zone 16, for example, by detecting when the outer bounding box 78 shadows the face zone 16. When this occurs, as shown at step 82 in Fig. 6 of the drawings, the processor 26 determines whether or not the drill rig 12 is facing the correct direction or, in other words, has the correct orientation relative to the face zone 16. It is required that, when controlling the drill rig 12 to tram into the face zone 16, it approached the face zone 16 drill string-end 56 first. A breach of this condition is shown at 84 in Fig. 5 A of the drawings where the drill rig 12 is shown approaching the face zone 16 with the drill string-end 56 at the trailing end, of the drill rig 12. Such a condition is prohibited and requires remedial action to be taken as will be described in greater detail below.

[0060] If the processor 26 determines that the drill rig is in the correct orientation relative to the face zone 16, the processor 26 then, at step 86, determines whether or not the drill rig 12 is on the correct heading. Implementation of steps 82 and 86 is described in greater detail with reference to Fig. 7 of the drawings. The processor 26 determines a point 87 (Fig. 8) on the control zone line 68 closest to the drill string 54 of the drill rig 12 as shown at step 88 (Fig. 7). An imaginary datum line 89 is then generated from the point 87 on the control zone line 68 to the drill string 54 of the drill rig as shown at step 90. The datum line 89 is drawn from the control zone line to the drill string 54 to ensure that the orientation of the drill rig 12 is correct, i.e. that the drill rig 12 is approaching the face zone 16 drill string-end 56 first.

[0061] Secondly, the processor then determines whether or not an included angle 'A' between the datum line 89 and an imaginary reference line 91 representing the heading, or the direction of tramming, of the drill rig 12 falls within the predetermined parameters, i.e. within specified tolerances. If the included angle 'A' is within the specified tolerances, the processor 26 instructs the vehicle controller 14 to continue tramming until the drill string 54 is at the destination location of the face hole location 72 at which a blast hole is to be drilled as shown at step 94 in Fig. 7 of the drawings. The positioning of the drill rig 12 so that its drill string 54 is in the correct location is determined using the inner bounding box as shown at step 96 in Fig. 6 of the drawings.

[0062] The vehicle controller 14 manoeuvres the drill rig 12 so that the drill string 54 is brought into the required location to drill at the relevant blast hole location 72 as shown at step 98 of the drawings. Once the drill rig 12 is in the required location, the processor 26 instructs the vehicle controller 14 to stop tramming of the drill rig 12. The vehicle controller 14 lowers the jacks 64 to raise the tracks 62 off the substrate and allows drilling to commence as shown at step 100.

[0063] The permitted included angle 'A' may be between 0° and about 45° and, preferably, between 0° and about 30°. It will be appreciated that these ranges include the end points and all ranges and angles encompassed between these outer limits.

[0064] Fig. 5b shows, at 101 , a breach of the condition relating to the specified tolerance of the included angle 'A' illustrating a case where the drill rig 12 is approaching the face zone 16 at too large an included angle. Under such circumstances, remedial action is required to be taken as will be described in greater detail below.

[0065] If either of the required parameters are not met, i.e. that the drill rig 12 is

approaching with the drill-string end 56 trailing or the included angle falls outside the specified tolerances, the processor 26, via the decision engine 36, causes the operating system 20 to generate a discernible alarm condition and remedial action is initiated as shown at step 102 in Figs. 6 and 7 of the drawings.

[0066] The remedial action which is initiated is either effected under autonomous control, as shown at step 104, or requires an operator to initiate manual control of the drill rig 12 using the manual control module 40 of the operating system 20, as shown at step 106.

[0067] Under autonomous remedial action, the drill rig 12, under the action of the controller 14, is caused to tram away from the face zone 16, the drill rig 12 is repositioned and the drill rig 12 is then controlled to re-approach the face zone 16 provided the specified parameters or tolerances are met.

[0068] Instead, the decision engine 36 may determine that autonomous operation of the drill rig 12 is to be overridden by the operator, who may either be in the cab 42 of the drill rig 12 or located remotely of the drill rig 12 at a remote control centre. Once manual control of the drill rig 12 has been initiated, the drill rig 12 remains under manual operation until the drill string 54 of the drill rig 12 has been positioned at the destination location. [0069] While this embodiment has been described with reference to the establishment of the datum line being drawn from the control zone line 68 to the closest point on the drill string 12 to determine the angle of approach of the drill rig 12, it will be appreciated that the heading of the drill could be determined on other bases. For example, the control zone line 68 could, in certain circumstances, be omitted and the datum line drawn orthogonally with respect to the face edge 22 or with respect to an imaginary line drawn through the face hole locations 72. The datum line 89 and the reference line 91 are rectilinear lines or at least those parts of the lines 89 and 91 which intersect each other and/or the control zone line 68 are rectilinear.

[0070] The spacing of the control zone line 68 from the edge 22 is configurable by mine personnel inputting relevant data into the operating system 20 via the user interface 44. In particular, the distance between the edge 22 and the control zone line 68 is configured based on external factors such as, for example, the type of edge (e.g. a face edge or a high wall edge), hardness of a substrate of the bench 18, the type of vehicle being controlled in the control zone, or the like.

[0071] At present, with automated operation of drill rigs 12, it is not possible for the drill rigs 12 to drill blast holes autonomously at face hole locations due to the need to exercise caution when tramming close to the edge 22 of a bench 18. With the provision of the current disclosure, safety checks are enforced when tramming to a hole location 72 in the control zone 16. These safety checks require that the drill rig 12 must "reverse" into the face zone 16, drill string-end first and that only a predetermined, configurable, approach angle to the control zone line 68 is permissible. This allows safe, automated tramming of a drill rig 12 into the face zone 16 which was previously inaccessible in automated mode. As a result, the automated operation of a drill rig 12 is improved resulting in improved mining efficiencies with related economic benefits.

[0072] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A method of controlling a mine vehicle which includes

monitoring the passage of the vehicle as it automatically traverses the area towards the control zone;

assessing the orientation of the vehicle relative to the control zone to ensure that an operative component of the vehicle approaches the control zone first; and

manoeuvring the mine vehicle so that at least the operative component of the vehicle is positioned in vicinity of a predetermined destination location within the control zone provided the orientation of the vehicle relative to the control zone falls within predetermined

parameters.

2. The method of claim 1 which includes monitoring the position of the vehicle in the area and the position of the vehicle relative to the control zone.

3. The method of claim 1 or claim 2 which includes defining an outer bounding box surrounding at least an outer perimeter of the vehicle and an inner bounding box contained within the perimeter of the vehicle and surrounding at least the operative component of the vehicle.

4. The method of claim 3 which includes defining the outer bounding box and the inner bounding box to have a buffer of a preselected size.

5. The method of claim 3 or claim 4 which includes assessing the orientation of the vehicle when any part of the outer bounding box reaches a predetermined position relative to the control zone.

6. The method of any one of the preceding claims which includes assessing the orientation of the vehicle by generating a datum line associated with, and extending transversely, from the control zone.

7. The method of claim 6 which includes generating a substantially rectilinear datum line.

8. The method of any one of the preceding claims which includes further assessing the orientation of the vehicle by monitoring a heading of the vehicle relative to the control zone.

9. The method of claim 8 which includes assessing the heading of the vehicle by monitoring an approach angle of the vehicle relative to the control zone.

10. The method of claim 9 in which the control zone is defined by an edge and a spaced control zone line extending parallel to the edge and in which the method includes determining the orientation of the vehicle relative to the control zone line by monitoring the approach angle of the vehicle relative to the control zone line.

1 1. The method of claim 10 which includes determining the orientation of the vehicle by monitoring the approach angle of the operative component of the vehicle relative to the control zone line.

12. The method of claim 11 which includes, if the approach angle is within tolerance, manoeuvring the vehicle so that the operative component of the vehicle enters the control zone.

13. The method of any one of the preceding claims which includes taking remedial action by one of (a) repositioning the vehicle automatically and (b) converting from automated control to operator-controlled control of the vehicle if the orientation of the vehicle relative to the control zone falls outside the predetermined parameters.

14. A method of controlling a mine vehicle relative to a control zone of an area being traversed by the mine vehicle, the method including

15. The method of claim 14 which includes generating a substantially rectilinear datum line.

16. The method of claim 14 or claim 15 which includes generating a substantially rectilinear reference line.

17. The method of any one of claims 14 to 16 which includes at least partially defining the control zone by a control zone line extending in spaced parallel relationship relative to an edge of the control zone.

18. The method of claim 17 which includes generating the datum line to extend

substantially normal to the control zone line.

19. The method of claim 18 which includes generating the datum line between a point on the control zone line closest to the vehicle and the vehicle.

20. The method of claim 19 which includes generating the datum line between the point on the control zone line and the operative component of the vehicle.

21. The method of any one of claims 17 to 20 which includes generating the datum line from the point on the control zone line to the vehicle to ensure that an orientation of the vehicle relative to the control zone is correct.

22. A mine vehicle control system which includes

a vehicle controller, the vehicle controller being responsive to a control zone defining a part of an area traversed by a mine vehicle;

23. The system of claim 22 in which the processing unit is configured to generate the control zone and to process the data related to the vehicle, the processing unit further being operable to impart an outer bounding box about at least an outer perimeter of the vehicle and an inner bounding box contained within the perimeter of the vehicle and surrounding at least the component of the vehicle.

24. The system of claim 23 in which the processing unit is configured to define the outer bounding box and the inner bounding box to have a buffer of a preselected size.

25. The system of claim 23 or claim 24 in which the processing unit is configured to assess the orientation of the vehicle relative to the control zone as soon as any portion of the outer bounding box reaches a predetermined position relative to the control zone.

26. The system of any one of claims 23 to 25 in which the processing unit is configured to assess the orientation of the vehicle by monitoring a heading of the vehicle relative to the control zone.

27. The system of claim 26 in which the processing unit is configured to assess the heading of the vehicle by monitoring an approach angle of the vehicle relative to the control zone.

28. The system of claim 27 in which the processing unit is configured to generate a substantially rectilinear datum line extending transversely to the control zone and to monitor the approach angle of the vehicle relative to the datum line.

29. The system of claim 28 in which the control zone is defined by an edge and a spaced control zone line extending parallel to the edge with the datum line extending substantially normal to the control zone line.

30. The system of claim 29 in which the processing unit is configured to monitor the approach angle of the component of the vehicle relative to the datum line.

31. The system of any one of claims 22 to 30 in which the decision engine of the processing unit is operative, if the orientation of the vehicle relative to the control zone falls outside the predetermined parameters, to cause remedial action to be taken.

32. The system of claim 31 in which the decision engine is operative, where remedial action is required, to do one of (a) repositioning the vehicle automatically and (b) converting from automated control to operator-controlled control of the vehicle.

33. The system of claim 32 which includes operator-manipulated controls for enabling an operator to convert from automated control to operator-controlled control of the vehicle.

34. Software that, when installed on a computer, causes the computer to perform either of the methods of claims 1 to 21.