AU2016200781B1

AU2016200781B1 - Improved mining machine and method of control

Info

Publication number: AU2016200781B1
Application number: AU2016200781A
Authority: AU
Inventors: Mark Thomas DUNN; Chad Owen Hargrave; Jonathon Carey Ralston; David Charles Reid; Peter Bryan REID; Jeremy Patrick Thompson
Original assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Current assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Priority date: 2015-05-28
Filing date: 2016-02-08
Publication date: 2016-05-19
Anticipated expiration: 2036-02-08
Also published as: CN106194177B; CN111663943B; CN111663943A; AU2016200784B1; CN106194177A; AU2016200783B1

Abstract

A system for controlling a mining machine comprises a co-ordinate position determining device, at least one co-ordinate reference point and a processor. The processor is 5 connected to receive data relating to an absolute co-ordinate position determined by the position determining device and the at least one reference point. Data relating to the determined absolute co-ordinate position is corrected by reference to the at least one reference point. The processor is connected to generate further signals to activate a mining machine actuator, rail actuator and/or extraction device actuator based on the corrected 0 absolute co-ordinate position, the processor operating with at least one of the actuators such that the extraction device will cut, or attempt to cut to an intended cut profile.

Description

IMPROVED MINING MACHINE AND METHOD OF CONTROL FIELD OF THE INVENTION This invention relates to a mining machine and method whereby a mining machine can be 5 controlled to move across a seam containing product to be mined. DESCRIPTION OF PRIOR ART In the mining of coal, processes have been developed which are referred to as longwall mining processes. In these processes, among other components, a movable rail is placed to span across a coal seam. A mining machine is provided with at least one shearing head and 0 the mining machine is moved to traverse along the rail from side-to-side of the seam, and the shearing head or heads are manipulated upwardly and downwardly to shear coal from the face of the seam. Throughout each pass, the rail is moved forwardly toward the seam behind the path of the mining machine. The mining machine is then caused to traverse the seam in the opposite direction in order to repeat the shearing process. During this return 5 traverse the shearing head(s) may also if desired be manipulated upwardly and downwardly to remove further coal from the seam. The process is repeated until all coal in the planned extraction panel is completed. Thus, by advancing the rail forwardly towards the seam by a suitable distance after each pass, it is possible to progressively move into the seam with an approximate equal depth of .0 cut with each pass. In practice, inaccuracies develop with each subsequent pass due to slippage of a powered roof support advance system which moves the rail, resulting in the depth of cut varying across the face of the seam. This, in turn, leads to reduced production yields and unnecessary mechanical loading and stresses on the rail and powered roof support advance 25 system. Such inaccuracies are attributable, in large part to the fact that the powered roof support advance system moves the rail forwardly by a set incremental amount at each pass. Thus, because of the slippage of the powered roof support advance system, the inaccuracies accumulate after many passes of the machine. Desirably, the rail is expected to extend in a straight line, but, because of the slippage, the rail is progressively moved so that 30 it eventually has a curvilinear or snake like path. This, in turn, results in down time in attempting to reposition the rail to correct these accumulated inaccuracies. 1 US6857705 addresses this problem through the use of a 2D co-ordinate determining positioning means to determine the absolute position of the mining machine at a plurality of locations as the mining machine transverses across the face of the coal seam. While this method addressed the problem of accumulated inaccuracies due to slippage of the powered 5 roof support advance system, there is still scope for further improvements in controlling the alignment of the mining machine as it transverses across the coal seam. STATEMENT OF THE INVENTION In a first aspect of the present invention there is provided a system for controlling a mining machine throughout a shearing cycle comprising: 0 A. a mining machine comprising: (i) a shearing head mounted on a moveable carriage, said shearing head for mining product from a seam as said moveable carriage traverses from side-to-side across a mining face of said seam on a rail which 5 extends from side-to-side across the seam; (ii) a rail actuator for moving the rail towards said seam; (iii) a shearer head actuator for moving the shearer head toward a seam boundary; (iv) at least 2D co-ordinate position determining device for determining the .0 absolute co-ordinate position in space of the mining machine and/or the rail at each of a plurality of locations along the rail, said position determining device providing current absolute co-ordinate position output data signals therefrom; (v) a processor connected to receive the output data signals and to 25 generate further signals to: a. activate said rail actuator to thereby displace or attempt to displace said rail a distance towards said seam based on the determined current absolute co-ordinate position of that part of the mining machine or rail as distinct from an expected co-ordinate 30 position , to assume a coordinate position of an intended cut profile; and/or b. activate said shearer head actuator to displace or attempt to displace said shearer head a distance towards a seam boundary based on a determined current absolute co-ordinate position of the 35 mining machine or rail means as distinct from an expected 2 coordinate position, to assume a coordinate position of an intended cut profile; said processor operating with at least one of said actuators at various locations along the length of the rail, so said shearing head will cut, or attempt to cut to the intended 5 cut profile, B. at least one co-ordinate reference point each providing at least a 2D co ordinate position, each reference point disposed at the main gateroad and/or tail gateroad, wherein the processor is connected to receive data relating to the at least one co 0 ordinate reference point. The mining machine or rail actuator preferably displaces or attempts to displace said mining machine or rail a distance in a substantially horizontal plane towards said seam. The extraction device (e.g. shearer head) actuator preferably displaces or attempts to displace said extraction device (e.g. shearer head) a distance in a substantially vertical plane. 5 The present invention enables the mining machine and the extraction device to be more accurately positioned and have greater certainty regarding its position relative to the seam to be mined. At least one of the reference points is preferably an absolute co-ordinate reference point (or primary reference point). .0 The system of the present invention is able to reduce the accumulation of errors built up in the position determining device and enable a more accurate measured cut profile to be established through providing a more accurate intended cut profile. Furthermore, the intended cut profile may be better aligned within a seam model, such that the mining machine can optimise operational settings based upon a better understanding of where the 25 extraction device(s) (e.g. shearer head(s)) is/are relative to the characteristics of the coal seam and the surrounding environment. To improve the accuracy of the intended cut profile, the input or the output of the position determining device may be corrected. In one embodiment, the absolute co-ordinate position output signal from said position determining device is corrected by reference to the one or 30 more primary reference points. In an alternative embodiment, the absolute co-ordinate position of said determining device is corrected by reference to the at least one absolute co ordinate primary reference points. 3 The at least 2D co-ordinate position determining device may be located in any suitable position which allows for mining machine, moveable carriage and/or rail position to be determined. The at least 2D co-ordinate position determining device is preferably carried by the mining machine, moveable carriage and/or the rail. The at least 2D co-ordinate position 5 determining device preferably is a 3D co-ordinate position determining device. Preferably, the at least one absolute co-ordinate primary reference points are used to correct the intended cut profile against one or more reference points. The reference points are preferably a plurality of current absolute co-ordinate positions which preferably extends along the main gateroad and/or the tail gateroad. 0 The at least one extraction device(s)/shearing head(s) preferably comprises a rotating cutting device. Mining machine The mining machine may include a longwall miner (including the associated rail, roof supports, drives, conveyor, stage loader and crusher), a continuous miner, a road header; a 5 shuttle car; a flexible conveyor train; a plough, or any other machine equipment with an extraction device to remove material from the seam. Intended cut profile The intended cut profile comprises a horizontal plane and a vertical plane which may be represented in 3D Cartesian coordinates in the (x,y) and (x,z) planes respectively. .0 Preferably the intended cut profile in the horizontal plane is a straight line, which enables increased coal extraction to be achieved (e.g. for longwall mining moveable carriage travels in a straight line between the main and tail gateroad). However, it would be understood that in some embodiment, a non-linear intended cut profile may be preferred depending upon the seam configuration. As the mining machine or rail actuator may not be able to efficiently 25 correct the actual profile to a straight line profile within a single cycle, the intended cut profile may be an intermediate between the actual cut profile and a straight line. Within the vertical plane, the intended cut profile may be straight or may follow the top and/or bottom boundary of the coal seam. Sensor outputs which identify the seam boundaries are preferably entered into the seam model to enable the processor to generate signals to the shearing head 30 actuator to control the shearing head within the identified seam boundaries. This ensures improved coal extraction efficiencies without the extraction device (e.g. shearing heads) transgressing outside the target coal seam. The intended cut profile may also be used in reference to roadway development by continuous miners and roadheaders. 4 Interpolation and Extrapolation Preferably the at least one reference points are used to correct the intended cut profile at one or both ends of the target seam (i.e. at the main or tail gateroad end of the target seam). The intermediate positions of the intended cut profile are preferably determined through 5 interpolation or extrapolation. More preferably, one or more absolute co-ordinate primary reference points are used to directly correct the intended cut profile at each end of the target seam and indirectly correct the intermediate positions of the intended cut profile through extrapolation. Linear Interpolation or extrapolation may be used or more sophisticated analytical 0 techniques may be adopted as known by those skilled in the art. Secondary reference points The system preferably comprises one or more secondary reference points. Secondary reference points are reference points which have been generated through reference to the primary reference point. A secondary reference point may include identifying characteristics 5 of the cut seam face detected by one or more sensors on the mining machine, rail or roof support system. For example, an infra--red detector in combination with the position determining device provides input into the processor to generate a characteristic thermal image which forms part of the seam model. The thermal map generated through a trailing shearer head is then matched up to the thermal map generated through a leading shearer .0 head in the next cutting cycle. Any spatial matching error between the two thermal images and their absolute co-ordinates positions may be used as input into a correction algorithm in the rail moving control and/or the extraction device (e.g. shearer head) moving control. Secondary reference points may be generated at the main and/or tail gateroads and/or the mine cutting surface (i.e. along the measured cut profile). 25 The correction of the intended cut profile preferably results in adjustments to the rail moving actuator and/or the extraction device (e.g. shearer head) actuator. In one embodiment, correction of one or more absolute co-ordinate primary reference points includes both feedback and feedforward correction. The feedback correction is preferably derived from the one or more reference points (primary and/or secondary) and the 30 feedforward correction is preferably derived from the trend in corrections over a plurality of cut cycles. The feedforward correction provides correction compensation for time dependent factors such as creep or systematic error drift in the position determining device. The use of 5 a feedforward correction overcomes the deficiencies in relying upon interpolation or extrapolation techniques alone to correct the intermediate points within the cut profile. The correction may also include input derived from measured variations of the distance between primary reference points along a gateroad surveyed distance. Variations in the 5 measured and originally surveyed values at any one cut cycle or a trend in said variations over a series of cycles may be used as input into the feedback and feedforward correction respectively. The data relating to the at least one reference points is preferably the absolute spatial co ordinates of the reference points where they are known (i.e. primary reference points) or the 0 spatial co-ordinates which are derived from a primary reference point (e.g. a secondary reference point). Through determining the relative position of the mining machine and the one or more reference points, the processor is able to compare the mining machine spatial position determined through use of the at least one reference points and compare the spatial position determined by the position determining device. 5 In a preferred embodiment, a laser range sensor is used to determine the relative position of the mining machine and the one or more reference points. Although the person skilled in the art would appreciate that other appropriate means may also be used to collect data from one or more of the primary reference points for input into the processor. In an alternative embodiment, the determination of the relative position of the reference point(s) and the .0 mining machine is estimated through knowledge of the cut model (e.g. estimated progression of the rail per extraction cycle). The reference point(s) may be determined by the at least 2D co-ordinate position determining device or independently surveyed. The discrepancy between the two spatial positions derived from different methods may be used to correct the intended cut profile of the mining machine. This is typically performed when 25 the mining machine has completed traversing across the mining seam (i.e. at the main or tail gateroad). At this point the processing means calculates the intended cut profile prior to traversing back across the mining face along a corrected path (longwall mining embodiment). The process is preferably repeated during each cycle (i.e. at the same gateroad) or half cycle (i.e. at each opposing gateroad). 30 The data is preferably the 2D or 3D spatial position of the primary reference point. The primary reference point(s) may also include identifiers, such as RFID tags which enable other information to be attached. Alternatively, the primary reference points may be reflective identifiers (e.g. reflective discs or plates attached to the gateroad wall) which may be used in combination with the laser range sensor. In embodiments using reflective identifiers, the 35 surveyed co-ordinates are preferably input into the processor prior to the commencement of 6 the mining activity within said surveyed co-ordinates (e.g. after the survey has been completed and before the mining activity has commenced). Conventional laser range sensors have drawbacks relating to safety requirements which prevented their effective use in underground coal mines. Preferably, the laser range 5 sensors used in the present invention conforms to one or more of International standard IEC 60079-0; IEC 60079-1; US standards: ANSI/UL1 203:2006, British standards BS EN 60079 1:2007; and Australian standards AS60079.1:2007. Preferably, the system further comprises one or more sensors carried entirely by one of the movable carriage and the rail means collecting seam data to feed into a seam model. 0 It will be appreciated that optional features of systems for controlling a mining machine according to other aspects of the invention may also be optional to the system according to the first aspect where appropriate. In a second aspect of the present invention there is provided a process for controlling a mining machine as previously defined comprising the steps of: 5 A. traversing the mining machine across a mining face of a seam; B. providing the processor at least 2D co-ordinate position from at least one co ordinate reference point, each reference point disposed at the main gateroad and/or tail gateroad; and C. correcting the current absolute co-ordinate position output signal from said .0 position determining device by reference to the at least one co-ordinate reference points; or correcting the current absolute co-ordinate position by reference to the at least one co-ordinate reference points. Preferably, the processor is provided with the at least 2D co-ordinate position from at least one co-ordinate reference point once the mining machine has completed a traverse across 25 the mining face of the seam. In a third aspect of the present invention there is provided a system for controlling a mining machine comprising: (i) an at least 2D co-ordinate position determining device for determining an absolute co-ordinate position in space of: 30 the mining machine; and/or a rail along which an extraction device of the mining machine traverses from side-to-side across a mining face of a seam, 7 the absolute co-ordinate position being determined at each of a plurality of locations of the mining machine and/or the rail along a mining face of a seam: (i) at least one co-ordinate reference point, each providing at least a 2D co ordinate position; and 5 (ii) a processor connected to receive data relating to: the determined absolute co ordinate position of the mining machine and/or rail; and the at least one co ordinate reference point, wherein the data relating to the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to the at least one co-ordinate 0 reference point, and wherein the processor is connected to generate further signals to: a. activate a mining machine or rail actuator for moving the mining machine or rail towards said seam to thereby displace or attempt to displace said mining machine or rail a distance towards said seam based on the corrected absolute 5 co-ordinate position of the mining machine or rail to assume a co-ordinate position of an intended cut profile; and/or b. activate an extraction device actuator for moving the extraction device towards a seam boundary to displace or attempt to displace said extraction device a distance towards the seam boundary based on the corrected .0 absolute co-ordinate position of the mining machine or rail to assume a co ordinate position of an intended cut profile, said processor operating with at least one of said actuators so said extraction device will cut, or attempt to cut to the intended cut profile. Preferably, each reference point is disposed at a main and/or tail gateroad. 25 Preferably, the absolute co-ordinate position is determined at each of a plurality of locations along the rail (i.e. along the mining face of the seam). In one embodiment, the at least one reference point comprises one or more primary reference points. Additionally or alternatively, the at least one reference point comprises one or more secondary reference points. 30 Preferably, the at least one co-ordinate reference point is used to correct the intended cut profile. Preferably the at least one reference point is used to correct the intended cut profile at one or both ends of the target seam (i.e. at the main or tail gateroad end of the target seam). The intermediate positions of the intended cut profile are preferably determined through 8 interpolation or extrapolation. More preferably, one or more absolute co-ordinate reference points are used to directly correct the intended cut profile at each end of the target seam and indirectly correct the intermediate positions of the intended cut profile through extrapolation. Linear Interpolation or extrapolation may be used or more sophisticated analytical 5 techniques may be adopted as known by those skilled in the art. Preferably, the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to at least two co-ordinate reference points. In some embodiments, the determined absolute co-ordinate position of the mining machine and/or rail may be corrected by reference to at least one co-ordinate reference point located 0 along the main gateroad and at least one co-ordinate reference point located along the tail gateroad. Preferably, the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to at least two co-ordinate reference points located along the main gateroad and at least two co-ordinate reference points located along the tail gateroad. 5 In one embodiment, correction of the determined absolute co-ordinate position of the mining machine and/or rail includes both feedback and feedforward control mechanism. The feedback correction is preferably derived from the one or more reference points (primary and/or secondary) and the feedforward correction is preferably derived from the trend in corrections over a plurality of cut cycles. The feedforward control mechanism may be .0 derived from comparisons between at least one current co-ordinate position and their corrections by reference to the at least one co-ordinate reference point over a plurality of cutting cycles. The feedforward correction provides correction compensation for time dependent factors such as creep or systematic error drift in the position determining device. The use of a feedforward correction overcomes the deficiencies in relying upon interpolation 25 or extrapolation techniques alone to correct the intermediate points within the cut profile. Preferably, the data relating to the absolute co-ordinate position determined by the position determining means is corrected once the mining machine has completed a traverse across the mining face of the seam. In an embodiment, a laser range sensor is used to determine the relative position of the 30 mining machine, extraction device, moveable carriage and/or rail and the at least one reference point. Although the person skilled in the art would appreciate that other appropriate means may also be used to collect data from one or more of the at least one reference points for input into the processor. 9 The at least one co-ordinate reference point may comprise identifiers, such as RFID tags which enable other information to be attached. Alternatively, the reference point(s) may be reflective identifiers (e.g. reflective discs or plates attached to the gateroad wall) which may be used in combination with the laser range sensor. In embodiments using reflective 5 identifiers, the surveyed co-ordinates are preferably input into the processor prior to the commencement of the mining activity within said surveyed co-ordinates (e.g. after the survey has been completed and before the mining activity has commenced). Preferably, the at least one reference point is a 3D co-ordinate position. The mining machine or rail actuator preferably displaces or attempts to displace said mining 0 machine or rail a distance in a substantially horizontal plane towards said seam. The extraction device actuator preferably displaces or attempts to displace said extraction device a distance in a substantially vertical plane. The system may further comprise one or more sensors collecting seam data to feed into a seam model. The one or more sensors may be used to generate a secondary reference 5 point. The secondary reference point may be generated through an identifying characteristic detected from the one or more sensors and the at least 2D co-ordinate position determining means. The one or more sensors may be selected from the group consisting of an infra-red spectrometer, a ground penetrating radar, a gamma ray emission detector and a range finding sensor. .0 The at least one co-ordinate reference point may further be used to align the cut model and the seam model. The mining machine is preferably a longwall miner, a continuous miner or a roadheader. The extraction device is preferably a shearer head or a cutting drum. The processor preferably operates with at least one of said actuators at various locations 25 along the rail or mining face. It will be appreciated that optional features of systems for controlling a mining machine according to other aspects of the invention may also be optional to the system according to the third aspect where appropriate. In a fourth aspect of the present invention, there is provided a process for controlling a 30 mining machine using a system according to the third aspect comprising the steps of: A. traversing the mining machine across a mining face of a seam; 10 B. providing the processor data relating to at least one co-ordinate reference point, each providing at least a 2D co-ordinate position; and C. correcting data relating to an absolute co-ordinate position determined by a position determining device by reference to the at least one co-ordinate 5 reference point. Preferably, each reference point is disposed at a main and/or tail gateroad. Preferably, the data relating to the absolute co-ordinate position determined by the position determining means is corrected once the mining machine has completed a traverse across the mining face of the seam. 0 In a fifth aspect of the present invention, there is provided a system for controlling a mining machine comprising: (i) an at least 2D co-ordinate position determining device for determining an absolute co-ordinate position in space of: the mining machine; and/or 5 a rail along which an extraction device of the mining machine traverses from side-to-side across a mining face of a seam, the absolute co-ordinate position being determined at each of a plurality of locations of the mining machine and/or the rail along a mining face of a seam; (ii) at least one co-ordinate reference point, each providing at least a 2D co .0 ordinate position, (iii) one or more sensors for collecting seam data, wherein at least one secondary reference point is generated through an identifying characteristic detected from the one or more sensors in combination with the at least 2D co-ordinate position determining means and with reference to the at least one co-ordinate 25 reference point; and (iv) a processor connected to receive data relating to: the determined absolute co ordinate position of the mining machine and/or rail; the at least one co ordinate reference point; and the at least one secondary reference point, wherein the data relating to the determined absolute co-ordinate position of the 30 mining machine and/or rail is corrected by reference to the at least one secondary reference point, and wherein the processor is connected to generate further signals to: a. activate a mining machine or rail actuator for moving the mining machine or rail towards said seam to thereby displace or attempt to displace said mining 35 machine or rail a distance towards said seam based on the corrected absolute 11 co-ordinate position of the mining machine or rail to assume a coordinate position of an intended cut profile; and/or b. activate an extraction device actuator for moving the extraction device towards a seam boundary to displace or attempt to displace said extraction 5 device a distance towards the seam boundary based on the corrected absolute co-ordinate position of the mining machine or rail to assume a coordinate position of an intended cut profile, said processor operating with at least one of said actuators so said extraction device will cut, or attempt to cut to the intended cut profile. 0 Preferably, the absolute co-ordinate position is determined at each of a plurality of locations along the rail (i.e. along the mining face of the seam). The processor preferably operates with at least one of said actuators at various locations along the rail or mining face. The generation of secondary reference points through identifying characteristics within the 5 seam provides the potential for the mining machine calibrate more frequency and thus reduced spatial positioning errors from extended periods of operation without calibration. Preferably, each reference point is disposed at a main and/or tail gateroad. In one embodiment the mining machine is controlled throughout a shearing/cutting cycle, as the mining machine traverses back and forth along a seam, such as a longwall mining .0 machine on a rail. In alternative embodiments, the mining machine is controlled in the development of roadways, including the construction of main gateroads and/or tail gateroads. The extraction device may be any suitable device which extracts material from a seam, including a shearer head or a cutting drum. 25 The identifying characteristic is preferably a portion of a marker band. A marker band is a differentiating layer or layers of material, which may result for differentiate geological compositions or structures, such as different coal macerals. Alternatively, the identifying characteristic may be a geological fault line. This may be identifiable through a discontinuity in the seam. 30 The identifying characteristic preferably comprises a plurality of geometrical or geological identifying characteristics geometrically spaced apart. An example of geometrical identifying characteristics geometrically space apart may include the intersection of the mining face and 12 a gateroad. An example of a geological identifying characteristics geometrically space apart may include a marker band which comprises a layer of material of different composition to its adjacent layers. In general, the greater the number of geometrical or geological identifying characteristics, 5 the lower the probability of the one or more sensors misidentifying the identifying characteristic. The identifying characteristic may be located on or beneath the mining face of a seam, or on or beneath the walls or roof of the roadway (e.g. tail gateroad or the main gateroad). While the identifying characteristics are preferably natural occurring features of the seam, in 0 some embodiments the identifying characteristics are artificially constructed features of the seam, such as geometric configuration of the seam through its interaction with the extraction device. In other embodiments, the identifying characteristic may comprise artificial identifying characteristics introduced in the course of the mining process. 5 The mining machine is preferably a longwall miner, a continuous miner or a roadheader. The extraction device is preferably a shearer head or a cutting drum. The one of more sensors is preferably selected from the group consisting of an IR sensor, visual camera, laser range finder, density meter and ground penetrating probe. It will be appreciated that optional features of systems for controlling a mining machine .0 according to other aspects of the invention may also be optional to the system according to the fifth aspect where appropriate. In a sixth aspect of the present invention, there is provided a process for controlling a mining machine using a system according to the fifth aspect comprising the steps of: A. traversing the mining machine across a mining face of a seam: 25 B. providing the processor data relating to at least one secondary reference point, the at least one secondary reference point generated through an identifying characteristic detected from one or more sensors in combination with an least 2D co-ordinate position determining means and with reference to at least one co-ordinate reference point; and 30 C. correcting data relating to an absolute co-ordinate position determined by a position determining device by reference to the at least one secondary reference point. 13 Preferably, each reference point is disposed at a main and/or tail gateroad. Preferably, the data relating to the absolute co-ordinate position determined by the position determining means is corrected once the mining machine has completed a traverse across the mining face of the seam. 5 In a seventh aspect of the present invention there is provided a system for controlling a mining machine comprising: (i) an at least 2D co-ordinate position determining device for determining an absolute co-ordinate position in space of: the mining machine; and/or 0 a rail along which an extraction device of the mining machine traverses from side-to-side across a mining face of a seam, the absolute co-ordinate position being determined at each of a plurality of locations of the mining machine and/or the rail along a mining face of a seam; (ii) at least one co-ordinate reference point, each providing at least a 2D co 5 ordinate position, (iii) a seam model of the seam to be cut (iv) a cut model of the seam that has been cut; and (v) a processor connected to receive data relating to: the determined absolute co ordinate position of the mining machine and/or rail; the at least one co .0 ordinate reference point; the seam model; and the cut model, wherein the data relating to the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to the at least one co-ordinate reference point and the seam model and cut model are aligned by reference to the corrected absolute co-ordinate position, and wherein the processor is connected to 25 generate further signals to: a. activate a mining machine or rail actuator for moving the mining machine or rail towards said seam to thereby displace or attempt to displace said mining machine or rail a distance towards said seam based on the corrected absolute co-ordinate position of the mining machine or rail to assume a coordinate 30 position of the intended cut profile; and/or b. activate an extraction device actuator for moving the extraction device toward a seam boundary to displace or attempt to displace said extraction device a distance towards the seam boundary based on the corrected absolute co ordinate position of the mining machine or rail to assume a coordinate position 35 of the intended cut profile, 14 said processor operating with at least one of said actuators so said extraction device will cut, or attempt to cut to the intended cut profile. Preferably, each reference point is disposed at a main gateroad and/or tail gateroad. Preferably, the absolute co-ordinate position is determined at each of a plurality of locations 5 along the rail (i.e. along the mining face of the seam). The processor preferably operates with at least one of said actuators at various locations along the rail or mining face. Preferably, the correction of the absolute co-ordinate position determining device occurs where the mining face intersects the main or tail gateroad. 0 Preferably, the correction of the absolute co-ordinate position determining device occurs at one or more points along the main gateroad or the tail gateroad. Through aligning the cut model and the seam model by reference to the corrected absolute co-ordinate position of the mining machine or rail, the spatial positioning of the cut model is known relative to the seam model and, as such, the spatial position of the mining machine 5 maybe known with a greater degree of certainty. Alignment of the seam model and the cut model is achieved preferably at one gateroad and more preferably at two gateroads (i.e. main and tail gateroad). As the cut model is a representation of the seam model after material from the seam has been extracted, an alignment between the cut model and seam model enables the mining .0 machine to orientate and adjust its future pathway based upon the mining machine previous interactions with the seam. The data relating to the determined absolute co-ordinate position of the mining machine and/or rail is preferably corrected by reference to the at least one co-ordinate reference point when the intended cut profile and a measured cut profile coincide with a common spatial or 25 geological reference point. For embodiments using a common spatial alignment, the alignment of the cut model and the seam model preferably occurs at or adjacent to the main gateroad or the tail gateroad where the position of the mining machine may be corrected by reference to a primary reference point (such as a survey marker) which is preferably positioned along the gateroad. At this 30 point the measured cut profile just completed (the actual cut profile of the mining machine against the intended cut profile) shares a common boundary with the intended cut profile, which the mining machine is about to progress along. 15 For longwall mining embodiments, this correction of the absolute co-ordinate position determining device preferably occurs at the completion of a cycle of extracting material along the intended cut profile (e.g. where the mining face intersects the main or tail gateroad). For 15A continuous miner and roadheader embodiments, the correction preferably occurs when the mining machine retreat at one or more reference points along the main or tail gateroad. The reference points may be primary or secondary reference points and may represent spatial positions which the mining machine has previously travelled to and corrected its position. 5 Preferably, the cut model is updated to correct the position of the measured cut profile. The corrected measured cut profile may be then compared to the intended cut profile from which it is based. Deviations between the intended cut profile and the resulting measured cut profile is preferably used as input into an updated intended cut profile and/or seam model. Deviations 0 between the two profiles may result in the intended cut profile being updated to pre emptively reduce the deviations between the profiles during a subsequent cutting cycle. Through sequential cuts along the mining face seam, the cut model comprises an increasing base of information which may be used to determine the intended cut profile, such that extraction efficiencies may be improved. 5 Preferably, the cut model comprises at least one measured cut profile, preferably at least two measured cut profiles and more preferably at least five measured cut profiles. The more measured cut profiles representing the traverses back and across the mining face, the greater the source of information which may be used to update the seam model through extrapolation or other data processing techniques. .0 Preferably, the cut model comprises characterising seam data and/or mining machine performance data tagged to the spatial coordinates or offset therefrom. In one embodiment, the cut model comprises the spatial positions of a marker band of the mining face and wherein the characteristics of the marker band in the cut model is used align the cut model and the seam model (i.e. geological reference point). In doing so, the spatial 25 position of the mining machine along the intended cut profile may be referenced against the marker band characteristics in the seam being cut and the marker band characteristics of the cut model. Preferably, the marker band in the seam and Cut model are referenced at equivalent point(s) across the mining face. In particular, the vertical height of the marker band of the seam being cut may be compared with the vertical height of marker band at the 30 equivalent position in the previous traversal across the mining face. The marker band characteristics may comprise the pathway of the marker band along the seam face, such a sensor on the mining machine may be able to register the positioning of the mining machine against the seam about to be mined (e.g. from the cut model / seam 16 model interface) and register the relative position of the marker band against the mining machine position on the intended cut profile. Distinctive characteristics, such as marker band discontinuities or inflexion points or geological variations may be utilised from the cut model onto the seam model, such that the intended cut profile may be updated. 5 It will be appreciated that optional features of systems for controlling a mining machine according to other aspects of the invention may also be optional to the system according to the seventh aspect where appropriate. 0 In an eighth aspect, there is provided a process for controlling a mining machine using a system according to the seventh aspect comprising the steps of: A. traversing the mining machine across a mining face of a seam: B. providing the processor data relating to at least one co-ordinate reference point, each providing at least a 2D co-ordinate position; 5 C. correcting data relating to an absolute co-ordinate position determined by a position determining device by reference to the at least one co-ordinate reference point; and D. aligning a seam model of the seam to be cut and cut model of the seam that has been cut by reference to the corrected absolute co-ordinate position .0 Preferably, each reference point is disposed at a main and/or tail gateroad. In a ninth aspect of the present invention, there is provided software that, when executed by a computer, causes the computer to perform a process according to the second, fourth, sixth or eighth aspects. In a tenth aspect of the present invention, there is provided an apparatus comprising: 25 (i) a system according to the first, third, fifth or seventh aspects; and (ii) a mining machine. The mining machine may comprise an extraction device mounted on a moveable carriage, said shearing head for mining product from a seam as said moveable carriage traverses from side-to-side across the seam. 30 The mining machine may further comprise a rail actuator, a mining machine actuator and/or an extraction device actuator. The mining machine or rail actuator preferably displaces or attempts to displace said mining machine or rail a distance in a substantially horizontal plane towards said seam. The extraction device actuator preferably displaces or attempts to displace said extraction device a distance in a substantially vertical plane. 17 The mining machine may be a longwall miner, a continuous miner or a roadheader. The extraction device may be a shearer head or a cutting drum. Definitions For the purposes of the present invention, reference to a single feature also encompasses 5 the plural. For example a mining machine comprising a shearing head also encompasses the embodiment of a mining machine comprising two shearing heads. Intended cut profile The predetermined path of the extraction device (e.g. shearer) along or across the current mining face based upon the input of the position determining means (e.g. INS). The intended cut profile is preferably derived from the seam model. The intended cut 0 profile preferable extends the length of the mining face for longwall mining applications and at least 10 metres and more preferably at least 50 metres in other applications (e.g. roadway development). Measured cut profile The measured path of the extraction device (e.g. shearer) after it has progressed or traversed across the mining face. 5 Cut model The at least 2D (preferably 3D) model or map of the spatial coordinates of the mining seam which has been mined. The model may also include characterising seam data and/or mining machine characterising/performance data tagged (spatially registering a seam characterising datum) to the spatial coordinates or offset therefrom. The cut model preferably represents at least 50%, more preferably at least 80% and most .0 preferably 100% of the extracted material (i.e. historical path of the mining machine). Preferably, the cut model represents at least 2 metres, more at least 5 meters and even more preferably at least 50 metres of the extracted material behind the machine (i.e. not in the direction of extraction). Seam model The at least 2D (preferably 3D) model or map of the mining seam which has 25 yet to be mined. This model is preferably established initially from exploration data and may be refined by extrapolation of as-mined information from the cut model into the yet uncut seam. The seam data may include characterising seam data derived from exploration data such as rock mass defects and faulting structures, composition, hardness, propensity for cave-in, surface and in-seam borehole drilling data, geophysical logging data and 2D and 3D 30 seismic data as well as topographical data of the seam ahead of mining based on seismic signals using the at least 2D co-ordinate position determining device to accurately locate the absolute position of the seismic source. The seam characteristics may be surface characteristics or may be characteristics of a layer within the seam, which may represent 18 thickness of one or more extraction cycles of the mining machine. The model may include characterising seam data and/or machine characterising/performance data tagged to the spatial coordinates or offset therefrom. The model may also comprise spatial and characterising data relating to the material adjacent to the seam to be mined (e.g. 5 underburden, interburden, and/or over-burden). The characterising data is preferably relevant to determining the seam boundary and/or the stability of the seam as it is being mined by the mining machine. Preferably, the seam model represents at least 2 metres, more at least 5 meters and even more preferably at least 50 metres of the seam in front (i.e. direction of extraction) of the 0 mining machine. It is to be understood that throughout this disclosure unless stated otherwise, intended cut profiles, measured cut profiles, cut models, seam models and the like refer to data structures, which are physically stored on data memory or processed by the processor. Extrapolation for the purposes of the present invention means the determination of 5 intermediate spatial position along a cut/seam model by prediction using corrected spatial positions at both the main and tail gateroad of the cutting surface. Interpolation for the purposes of the present invention means the determination of intermediate spatial position along a cut/seam model by prediction using corrected spatial positions at either the main or tail gateroad end of the cutting surface. .0 Primary reference points are identifying points of an absolute co-ordinate position. The co ordinate position is preferably 1 D, more preferably 2D and most preferably 3D. The reference points may be identifiable through use of a sensor. To this ends, the reference point may include a reflective surface, RFID tag or unique compositional, physical or thermal property of the spatial position which can be detected by an on-board sensor of the mining 25 machine or rail moving means. Secondary reference points are identifying points determined in reference to a primary reference point or the position determining means. Preferably the secondary reference point is determined by reference to the primary reference point. By reference to a reference point for the purposes of the present invention means that the 30 spatial co-ordinates of the reference point are used, preferably in an algorithm executed by a processor. Brief description of the figures 19 Figure 1 is a schematic diagram of a longwall mining machine cutting a coal seam between a main and tail gateroad from a top down perspective. Figure 2 is a schematic diagram of the control input for the shearer head and rail. Figure 3a & 3b are schematic diagrams of the shearing head progressing towards the main 5 gateroad (3a) and back towards the tail gateroad (3b), with on-board sensors mapping the spatial co-ordinates of a unique coal seam characteristic. Figure 4 is a schematic diagram showing a marker band within a seam (solid line) together with the spatial position of the marker band during pervious cutting cycles (dashed line). Figure 5 is a schematic diagram of a continuous miner cutting a main gateroad from a coal 0 seam. Detailed description of the preferred embodiments With reference to Figure 1, there is an underground coal deposit 5 comprising a main gateroad 10 and a tail gateroad 15. The gateroads define the target coal seam 20 to be 5 mined. The gateroads comprise a number of reference points or identifiers 25, which may in the form a reflective marker/identifier. The 3D co-ordinates of the reference points are determined by surveying of the gateroad prior to the commencement extracting coal from the target seam. The surveying is typically performed from a reference or zero plane 30. The mining machine 35 progressively traverses the cutting surface 40, with the roof supports .0 45 progressively moving forward to support the new exposed seam ceiling. The path of the mining machine is governed by an intended cut profile which forms part of the seam model comprising a 3D spatial model of the seam to be extracted. Upon the mining machine completing a traversal across the cutting surface, the enclosed range finding lasers mounted upon the mining machine determine the 3D co-ordinate spatial position (3D position) of the 25 mining machine through determining the distance between and mining machine and one or more reference points. Preferably the 3D position of the mining machine is determined through the use of two reference points. Triangulation and/or trilateration methods are preferably used to calculate the 3D position. The measured 3D position is compared against the current 3D position determined by the position determining device (Figure 2), which is 30 also mounted on the mining machine 35. The position determining means is preferably an inertia navigation device (INS) comprising gyroscopes and accelerometers. 20 The difference between the measured and current 3D position (A 1 ) is input into a correction algorithm operated within the processor. This output of the correction algorithm is entered into the shearing head and/or rail moving control and consequently determining actuator movement to control the spatial co-ordinates of the rail or mining machine including 5 components thereof (e.g. shearer head position). As the mining machine completes each traverse or cycle of the cutting surface 40, the cut model, which comprises a 3D spatial model of the seam that has been extracted, is updated. The cut model is able to store spatial and seam characterising data over a plurality of cutting cycles, such that trends can be analysis are used to correct the seam model. In one 0 embodiment, trends in the error between the measured and current 3D positions (A 1 , A 2 , A 3 ,

A

4 , ...) are used as input into the correction algorithm. The detection of time dependent trending of spatial errors may be used to reduce errors due to creep and/or drift in the INS. For example, if the spatial error of the mining machine as measured at the gateroad is progressively increasing, this observation may be used to pre-emptively correct this error. 5 This may be performed through a learning algorithm. While the 3D position of the mining machine may be corrected at either at the intersection of the cutting surface and the tail gateroad and/or main gateroad, preferably the correction of the mining machine position is achieved at multiple positions along the length of the cutting face. This is preferably achieved via using the gateroad corrections in combination with .0 interpolation or extrapolation techniques. The cut and seam model are also preferably updated at the same points in which the mining machine position is corrected. Using these techniques an updated intended cut profile is generated which incorporates calculated corrections to the current mining machine location as determined by the INS alone. When the mining machine completes the intended cut profile at either the tail or main 25 gateroad, the roof supports 45 perform a sequencing manoeuvre, referred to as "snaking", in which the roof supports are pushed forward a portion of the full web distance dependent upon the updated intended cut profile. The distance in movement forward of the roof supports is used to determine the relative distance between the cut model (mining face at the end of the cycle) and the seam model (mining face after the commencement of the 30 intended cut profile). Through establishing the relative spatial positions of the cut and seam model, the cut model may be used to update the seam model and pre-emptively adjust the intended cut profile. For example, a comparison between the intended cut profile and the measured cut profile across a mining face, may establish that one or more roof supports are repeatedly deviating from their expected web push distances. The cut model may be able to 35 detect such systematic or time dependent deviations and, as input into an algorithm, update 21 the seam model such the future intended cut profiles take these roof support anomalies into account. Alternatively, or in addition to, the intermediate points along the cutting seam surface may be determined through use of secondary reference points. As illustrated in Figure 3a, the 5 mining machine 50, traverses towards the main gateroad 55. As the machine progresses towards the main gateroad a sensor 60 in combination with the INS 65 maps out the characteristics of the trailing cut coal seam 70 onto a seam model. The seam model may include the seam boundary, such that the intended cut profile can incorporate a path such that the processor signals the shearer head moving actuator to move the shearer head 0 within the seam boundary. At the end of the cycle, the current 3D spatial position as determined by the INS is compared against the measured 3D spatial position determined by an enclosed laser range finder 75 with reference to one or more primary reference points 80. Any correctional adjustments are determined by the on-board processing unit (not shown). As the mining machine traverses 5 towards the tail gateroad (Figure 3b), the sensor 60 in combination with the INS 65 maps out the coal seam characteristics on the leading face (i.e. in front of the shearer's leading head). The data from the sensor(s) is provided to the seam model with the differences in the spatial positioning of the characteristic identifiers 70 used as input into the correction algorithm within the processing unit, with adjustments made, if required, to the mining machine .0 intended cutting profile as a result. The use of secondary reference points may also be used at intermediate positions between the primary reference points. A preferred sensor 60 for determining a coal seam characteristic is an IR or thermal sensor. One or more sensors may be used. The location(s) of the sensor(s) may vary to ensure that 25 that sufficient quality data can be obtained from the coal seam during its mapping in both the trailing and leading positions. A suitable IR or thermal sensor is described in US8622479, which is incorporated herein by reference. In an alternative embodiment, and where the environment permits, simultaneous localisation and mapping (SLAM) is used to use the localised physical characteristics of the 30 coal seam as a point/identifier of reference. Figure 4 illustrates a marker band 195 in the coal seam face which represents the interface between the seam model (coal to be extracted) and cut model (coal which has been extracted). The marker band comprises a geological characteristic 220. By aligning the cut 22 and seam models, the changing position of the geological characteristic over previous cutting cycles may be used to update the seam model, such that position of the geological characteristic may be predicted in the seam model. For an accurate prediction of the geological characteristic in the seam model, the spatial position of the geological 5 characteristic should be corrected during each cutting cycle. Figure 5 illustrates a continuous miner 200 extracting material in the formation of a roadway, such as a main gateroad 10. The gateroad may form part of a longwall mining operation or may form part of a room and pillar mining system. The intended cut profile of the continuous miner is determined from the seam model which comprises details of the seam from in-seam 0 borehole drilling data. The continuous miner comprises an INS which is corrected by reference to survey markers 25 which provide absolute 3D spatial positions. To form the main gateroad the continuous miner progressively extracts material from the gateroad. The INS of the continuous miner may be periodically corrected by reference to the survey markers. After the correction of the mining machine spatial position, the seam model, 5 including the intended cut profile is updated. The cut model, comprising the measured profile of the material which has been extracted, is also updated. The processor provides output signals to the actuators to signal the cutting drum to move upwards towards a seam boundary. The processor references a virtual seam boundary position from with a seam model through calculating the relative position of the cutting drum .0 within the seam model. Periodically, the continuous miner may retreat back along the gateroad and position itself adjacent a survey maker to compare the spatial position of the mining machine derived from the INS and derived from the survey marker and correct the INS accordingly. The updated intended cut profile preferably partially overlaps with the measured cut profile, as the mining 25 machine retraces its path over the profile which has already been extracted within the cut model before reaching the seam face, which acts as a reference point being the interface between the cut model and the seam model. In the same of different embodiment, prior to retreating along the gateroad, the continuous miner is preferably corrected against a survey marker (e.g. through the use of a range 30 finding sensor), such that upon returning to the same position adjacent the seam face, the INS reading may be compared against the known position of the INS when previously corrected. The repeated measurements of deviations in compared spatial positions may be used to gauge the accuracy and precision of the INS, such that calibration or adjustment to the sampling rate may be used to improve the INS performance. 23 The continuous miner may comprise a marker band detection sensor, such as an IR sensor, so that the continuous miner can identify characteristics in the seam which may be used as a secondary marker from which the INS spatial position may be corrected against, analogous to the method used in respect to the longwall miner illustrated in Figures 3a and Figure 3b. 5 24

Claims

1. A system for controlling a mining machine comprising: (i) an at least 2D co-ordinate position determining device for determining an 5 absolute co-ordinate position in space of: the mining machine; and/or a rail along which an extraction device of the mining machine traverses from side-to-side across a mining face of a seam, the absolute co-ordinate position being determined at each of a plurality of 0 locations of the mining machine and/or the rail along a mining face of a seam; (ii) at least one co-ordinate reference point, each providing at least a 2D co ordinate position, wherein each reference point is disposed at a main gateroad and/or tail gateroad; and (iii) a processor connected to receive data relating to: the determined absolute co 5 ordinate position of the mining machine and/or rail; and the at least one co ordinate reference point, wherein the data relating to the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to the at least one co-ordinate reference point, and wherein the processor is connected to generate further signals .0 to: a. activate a mining machine or rail actuator for moving the mining machine or rail towards said seam to thereby displace or attempt to displace said mining machine or rail a distance towards said seam based on the corrected absolute co-ordinate position of the mining machine or rail to assume a co-ordinate 25 position of an intended cut profile; and/or b. activate an extraction device actuator for moving the extraction device towards a seam boundary to displace or attempt to displace said extraction device a distance towards the seam boundary based on the corrected absolute co-ordinate position of the mining machine or rail to assume a co 30 ordinate position of an intended cut profile, said processor operating with at least one of said actuators so said extraction device will cut, or attempt to cut to the intended cut profile.

2. The system according to claim 1, wherein the in the at least one reference point 35 comprises: one or more primary reference points and/or one or more secondary reference points. 25

3. The system according to claim 1 or claim 2, wherein the at least one co-ordinate reference point is used to correct the intended cut profile. 5

4. The system according to claim 3, wherein the at least one co-ordinate reference point is used to directly correct the intended cut profile at one or both ends of the seam and indirectly correct intermediate positions of the intended cut profile through interpolation or extrapolation. 0

5. The system according to any one of the preceding claims, wherein the determined absolute co-ordinate position of the mining machine and/or rail is corrected by reference to at least two co-ordinate reference points.

6. The system according to any one of the preceding claims, wherein the determined 5 absolute co-ordinate position of the mining machine and/or rail is corrected by reference to at least one co-ordinate reference point located along the main gateroad and at least one co-ordinate reference point located along the tail gateroad.

7. The system according to any one of the preceding claims, wherein the determined .0 absolute co-ordinate position of the mining machine and/or rail is corrected using a feedback and a feedforward control mechanism.

8. The system according to claim 7, wherein the feedforward control mechanism is derived from comparisons between at least one current co-ordinate position and their 25 corrections by reference to the at least one co-ordinate reference point over a plurality of cutting cycles.

9. The system according to any one of the preceding claims, wherein a relative position of the mining machine, extraction device, moveable carriage and/or rail and the at 30 least one reference point is determined through use of a laser range sensor.

10. The system according to any one of the preceding claims, wherein the at least one reference point is a 3D co-ordinate position. 35

11. The system according to any one of the preceding claims, wherein the system further comprises one or more sensors for collecting seam data to feed into a seam model. 26

12. The system according to claim 11, where in the one or more sensors are selected from the group consisting of an infra-red spectrometer; ground penetrating radar, a gamma ray emission detector and a range finding sensor. 5

13. The system according to any one of the preceding claims, wherein the mining machine is a longwall miner.

14. The system according to any one of claims 1 to 12, wherein the mining machine is a continuous miner or a roadheader. 0

15. The system according to any one of the preceding claims, wherein the extraction device is a shearing head.

16. The system according to any one of claim 1 to 14, wherein the extraction device is a 5 cutting drum.

17. The system according to any one of the preceding claims, wherein the processor operates with at least one of said actuators at various locations along the rail or mining face. .0

18. A process for controlling a mining machine using a system according to any one of the preceding claims comprising the steps of: A. traversing the mining machine across a mining face of a seam; B. providing the processor data relating to at least one co-ordinate reference 25 point, each providing at least a 2D co-ordinate position, wherein each reference point is disposed at the main gateroad and/or tail gateroad; and C. correcting data relating to an absolute co-ordinate position determined by a position determining device by reference to the at least one co-ordinate reference point. 30

19. Software that, when executed by a computer, causes the computer to perform the process of claim 17 or claim 18.

20. An apparatus comprising: 35 (i) the system according to any one of claims 1 to 16; and (ii) a mining machine. 27