AU2016200789B1

AU2016200789B1 - Mining machine including a range finding system

Info

Publication number: AU2016200789B1
Application number: AU2016200789A
Authority: AU
Inventors: Ronald John Mcphee; Peter Bryan REID
Original assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Current assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Priority date: 2015-08-07
Filing date: 2016-02-08
Publication date: 2016-12-01
Anticipated expiration: 2036-02-08
Also published as: CN106441293B; CN106441293A; CN205981226U

Abstract

A mining machine (3) for use in a mine. The mining machine (3) has a range finding system (100) comprising: an electromagnetic output (102) to provide a first beam (104) of electromagnetic radiation along a first beam path (106); an electromagnetic input (108) to receive reflected electromagnetic radiation (110) of the first beam from an object (7) for determining a range (114) of the range finding system (100) from the object (7); and an enclosure (120) including a side wall (122) that surrounds a central axis (136) of the enclosure (120), the side wall (122) transparent to the electromagnetic radiation provided by the electromagnetic output (102). The electromagnetic output (102) and electromagnetic input (108) are disposed within the enclosure (120) such that the electromagnetic input (108) is located outside a second beam path (124) of a second beam (126) of electromagnetic radiation defined by a specular reflection (128) of the first beam (104) on the side wall (122). The mining machine (3) also has a data port (40) to output relative position data of the mining machine (3) to the object based on at least the determined range (114).

Description

ι 2016200789 12 Oct 2016 "Mining machine including a range finding system"

Technical Field [0001] The present disclosure relates to a mining machine including a range finding system. Background [0002] Mining machines may be required to move to different positions as required in a mine. Some mining machines are vehicles than may be navigated through routes in a mine site. The environment in a mine site may be pose challenges for known methods of determining the position of a vehicle.

[0003] Mine sites may include dusty conditions where traditional lane markers for roads may become obscured by dust and other debris. Furthermore, a mine site may operate underground or other conditions of low visibility that may affect visual observation. Furthermore, there may be difficulties with using navigation based on satellite transmitted signals (or locally transmitted signals) due to obstruction by the earth or signal multipath.

[0004] Other methods of navigation may be used, such as dead reckoning of position based on results of accelerometers and gyroscopes. Furthermore, the results of a speedometer and/or odometer may also be used. However, wheel slip on broken surfaces may lead to errors. Errors in dead reckoning systems may accumulate that in turn lead to long term inaccuracies in such systems.

[0005] Range information may also assist in determining the position of the observer as well as assisting in navigation. Range information, in conjunction with other information such as orientation of the object relative to the observer, can be used to construct maps with topographic information, or other forms of representation showing the position of object(s), and/or contours of the object(s) in the environment. Range information may also assist in determining the position of the observer to assist navigation.

[0006] In a known form, a range finding apparatus is provided at an observation location, and the apparatus includes a laser emitter to transmit a laser light beam towards an object.

The light beam is reflected off the object and the reflection of light is detected by a sensor of 2 2016200789 12 Oct 2016 the range finding apparatus. The time of flight of the light travelling from the laser emitter to the object, and from the object to the sensor is measured. This time of flight, in conjunction with the speed of light, is used to determine the range between the range finding apparatus at the observation location and the object.

[0007] Another challenge in a mine site is that it may include hazardous materials, such as flammable gasses, vapours, liquids, dust, etc. Accordingly, it may be important to reduce, minimise, or eliminate possible ignition sources from mining machines.

[0008] WO 2005/003875 (SANDVIK TAMROCK OY) discloses a method and a system for monitoring the location of a mining vehicle in a mine. WO 2007/009149 (COMMONWEALTH SCINTIFIC AND INDUSTRIAL RESEARCH ORGANISATION) discloses a method and apparatus for determining structural change in a mining operation.

[0009] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0010] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

Summary [0011] A mining machine compri ses: - a range finding system comprising: - an electromagnetic output to provide a first beam of electromagnetic radiation along a first beam path; - an electromagnetic input to receive reflected electromagnetic radiation of the first beam from an object for determining a range of the range finding system from the object; 3 2016200789 12 Oct 2016 -an enclosure including a side wall that surrounds a central axis of the enclosure, the side wall transparent to the electromagnetic radiation provided by the electromagnetic output; and - a first support element rotatable within the enclosure around a first rotation axis - wherein the electromagnetic output and electromagnetic input are disposed within the enclosure and supported by the first support element such that rotation of the first support element: steers the first beam provided by the electromagnetic output; and steers the electromagnetic input to receive the reflected electromagnetic radiation of the first beam from the object; and wherein the electromagnetic output is offset from the central axis so that the first beam path from the electromagnetic output to the side wall does not intersect the central axis and that the electromagnetic input is located outside a second beam path of a second beam of electromagnetic radiation defined by a specular reflection of the first beam on the side wall, - a data port to output relative position data of the mining machine to the object based on at least the determined range.

[0012] The mining machine may further comprise: - a processing device to: - determine a first position of the mining machine based on the relative position data and an object position of the object.

[0013] The mining machine may further compri se: - a first sensor system to determine movement data of the mining machine based on dead reckoning; wherein the processing device is further arranged to: - determine a second position of the mining machine based on: - the first position; and - the movement data of the mining machine based on dead reckoning.

[0014] The first position may be an absolute position.

[0015] The mining machine may further comprise: - a first sensor system to determine movement data of the mining machine 4 2016200789 12 Oct 2016 based on dead reckoning; - a processing device to: - determine a second position of the mining machine based on: - the relative position data; and - the movement data of the mining machine based on dead reckoning.

[0016] To determine a second position of the mining machine may be further based on: - a starting position data of the mining machine.

[0017] The range finding system may further comprise: - a data store, wherein an object position data associated with the object position of the object is stored in the data store.

[0018] The mining machine may comprise a longwall mining machine.

[0019] The mining machine may comprise a continuous mining machine.

[0020] The enclosure may further comprise one or more features which prevent the ignition of gas outside the enclosure by ignition triggers from the inside of the enclosure.

[0021] The one or more features may comprise sealing elements that in conjunction with the side wall seal an inside of the enclosure from outside of the enclosure such that the one or more sealing elements prevent ignition of gas outside the enclosure by ignition triggers from the inside of the enclosure.

[0022] The electromagnetic output may be offset from the first rotation axis so that the first beam path from the electromagnetic output to the side wall does not intersect with the first rotation axis.

[0023] The first rotation axis may be coaxial with the central axis.

[0024] The mining machine may further comprise: a second support element to provide support between the electromagnetic output and the first support element, wherein the second 5 2016200789 12 Oct 2016 support element is rotatable around a second rotation axis, and wherein rotation of the second support element steers the first beam provided by the electromagnetic output.

[0025] The second rotation axis may be perpendicular to the first rotation axis.

[0026] The mining machine may further comprise a controller module to steer the first beam to a plurality of orientations to provide a plurality of range determinations of the object(s) in a surrounding environment.

[0027] The plurality of range determinations of the object(s) in the surrounding environment may be represented as data in a three-dimensional point cloud.

[0028] The electromagnetic output may include a laser emitter to provide the first beam in the form of laser light. The electromagnetic input may include a light sensor to receive reflected laser light from the object.

[0029] The electromagnetic output may provide the first beam of electromagnetic radiation that is in one or more of the ultraviolet, visible, and/or infrared spectrums.

[0030] The side wall may be a cylindrical side wall.

[0031] The range finding system may further comprise: - a processor to generate a representation of the surrounding environment in three dimensions based on the plurality of range determinations.

[0032] The range finding system may further comprise: - a laser emitter to provide the first beam in the form of laser light, wherein the electromagnetic output includes a first reflector to redirect the first beam onto the first beam path.

[0033] The range finding system may further comprise: - a light sensor to detect reflected laser light from the object, wherein the electromagnetic input includes a second reflector to redirect reflected laser light towards the light sensor. 6 2016200789 12 Oct 2016 [0034] An angle of incidence between the first beam path and a surface normal of the side wall may be greater than 5 degrees.

[0035] An angle of incidence between the first beam path and a surface normal of the side wall may be less than a critical angle with of the side wall.

[0036] The range system may further comprise: - a second support element to provide support between the electromagnetic output and the first support element, wherein the second support element is rotatable around a second rotation axis wherein rotation of the second support element steers the first beam provided by the electromagnetic output, wherein the second rotation axis is perpendicular to the first rotation axis.

[0037] The range finding system may conforms to one or more of International standard IEC 60079-0; IEC 60079-1; US standards: ANSI/UL1203:2006, British standards BS EN 60079-1:2007; and Australian standards AS60079.1:2007.

[0038] The range finding system may comprise: - a laser emitter to provide a first beam of laser light along a first beam path; - a light sensor to receive reflected laser light of the first beam from an object for determining a range of the range finding system from the object; - an enclosure including a cylindrical side wall, the side wall transparent to the light provided by the laser emitter, wherein the enclosure includes one or more features which prevent the ignition of gas outside the enclosure by ignition triggers from the inside of the enclosure; and a first support element rotatable within the enclosure, wherein the laser emitter and light sensor are supported by the first support element such that rotation of the first support element steers the first beam provided by the laser emitter; and wherein the laser emitter and light sensor are disposed within the enclosure such that the light sensor is located outside a second beam path of a second beam of laser light defined by a specular reflection of the first beam on the cylindrical side wall.

[0039] The range finding system may further comprise a controller to steer the first beam towards a reflector; 7 2016200789 12 Oct 2016 determine an intensity value indicative of an intensity of light reflected off the reflector and received by the light sensor; and determine a level of contamination by coal dust particles based on the intensity value.

[0040] A method of monitoring a position of a mining machine comprises: - receiving, from a data port in the above mining machine, relative position data of the mining machine to an object having an object position; - receiving an output of a first sensor system indicative of movement data of the mining machine based on dead reckoning; - determining a second position of the mining machine based on: - the relative position data of the mining machine; and - the movement data of the mining machine based on dead reckoning.

[0041] The method may further comprise the step of; - determining a first position of the mining machine based on the relative position data of the mining machine to the object and the object position.

[0042] The step of determining a second position of the mining machine may be further based on the first position of the mining machine.

[0043] The method may further comprise: - receiving, from a data store, an object position data associated with the object in the data store; wherein the step of determining the first position is further based on the received object position data associated with the object.

[0044] The step of determining a second position of the mining machine may be further based on a starting position data of the mining machine.

[0045] A method of determining structural changes in a tunnel in a mining operation comprises: - receiving a first profile scan of the tunnel, wherein the first profile scan is based on receiving a plurality of relative position data from a data port in the above mining machine; 2016200789 12 Oct 2016 8 - storing the first profile scan in a data store; - subsequently receiving a second profile scan of the tunnel, wherein the second profile scan is based on receiving a plurality of relative position data from the same mining machine or different sensor system; and - processing the first profile scan and the second profile scan to determine any structural change of the surfaces of the tunnel corresponding to deformation in profile of the tunnel.

[0046] The tunnel may be within a coal mine.

[0047] The method may include performing a plurality of range determinations to a plurality of points on a coal face.

[0048] Optional features described of any aspect of machine or method or system, where appropriate, similarly apply to the other aspects also described here.

Brief Description of Drawings [0049] Examples of the present disclosure will be described with reference to: [0050] Fig. lisa top view of a mining machine traversing in a mine; [0051] Fig. 2 is a perspective view of a range finding system providing a first beam of electromagnetic radiation to an object for determining a range to the object; [0052] Fig.3 is a flow diagram of a method of monitoring a position of a mining machine; [0053] Fig. 4 is a flow diagram of a method of determining structural changes in a tunnel; [0054] Fig. 5a is a vertical cross-sectional view through a tunnel showing structural change over time of the profile of the tunnel walls and/or roof; [0055] Fig. 5b is a vertical cross-sectional view of a tunnel showing the mining machine; 9 2016200789 12 Oct 2016 [0056] Fig. 6 is a diagrammatic view showing a 3D cut-away of a longwall underground coal mining operation; [0057] Fig. 7 is a side view of a continuous mining machine; [0058] Fig. 8a a schematic of linked systems in a mining machine; [0059] Fig. 8b illustrates mining machines in communication with a communications network and other network elements; [0060] Fig.9 illustrates a simplified view of a range finding system positioned to measure the distance of object in a surrounding environment; [0061] Fig. 10 is a perspective view of the electromagnetic output, electromagnetic input, and first and second support elements of the range finding system; [0062] Fig. 11 is a side view of the range finding system of Fig. 2 showing the first beam provided by the electromagnetic output and reflected electromagnetic radiation of the first beam that is received by the electromagnetic input; [0063] Fig. 12 is a top view of the range finding system of Fig. 11; [0064] Fig. 13 is a simplified top view of the range finding system of Fig. 11 showing the electromagnetic output in three different azimuth orientations around a first rotation axis, and showing an example of refraction of the first beam; [0065] Figs. 14(a) to 14(c) is a simplified side view of Fig 11 showing the electromagnetic output in three different elevation orientations around a second rotation axis, and showing an example of effects of refraction of the first beam; [0066] Fig. 15 is a schematic of the range finding system with a controller module, a computer system and a display; [0067] Figs. 16(a) to 16(c) illustrate the range of possible elevations of the first beam in one form of range finding system; ίο 2016200789 12 Oct 2016 [0068] Figs. 17(a) to 17(d) are perspective views of alternative forms of an enclosure of the range finding system; [0069] Figs. 18(a) and 18(b) are perspective views of an electromagnetic input having a hood to shield the magnetic input from unwanted electromagnetic radiation; [0070] Figs. 19(a) and 19(b) are perspective views of a range finding system including reflectors for testing operation of the range finding apparatus; [0071] Fig. 20 is a top view of the range finding apparatus showing the electromagnetic output and input in two configurations for determining range from the same location on the object; [0072] Figs. 21(a) and 21(b) are top views of alternative forms of the range finding apparatus; and [0073] Figs. 22(a) to 22(c) are top view of alternative forms of the enclosure of the range finding system.

Description of Embodiments

Overview [0074] An overview of the mining machine 3 will now be described with reference to Figs. 1 and 2. The mining machine 3 includes a range finding system 100 to determine relative position data of the mining machine 3 to an object 7 with an object position. The object 7 may be any object, such as a wall 12 of a mine that can be detected by the range finding system 100.

[0075] The range finding system 100 of the mining machine 3 will now be briefly described with reference to Fig. 2. The range finding system 100 includes an electromagnetic output 102 to provide a first beam 104 of electromagnetic radiation along a first beam path 106 towards an object 7. The first beam 104 is reflected from the object 7 to provide reflected electromagnetic radiation 110. The range finding system 100 also includes an electromagnetic input 108 to receive reflected electromagnetic radiation 110 of the first beam 11 2016200789 12 Oct 2016 from the object 7 for determining a range 114 of the range finding system 100 from the object 7. The range 114 of the range finding system 100 from the object 7 may then be used to determine a range between the mining vehicle 3 and the object 7, which may be used to determine at least part of the relative position data of the mining machine 3 to an object 7.

The system 100 also includes an enclosure 120 having a side wall 122 surrounding a central axis 136 that is transparent to the electromagnetic radiation provided by the electromagnetic output 102. The electromagnetic output 102 and the electromagnetic input 108 are disposed within the enclosure 120 such that the electromagnetic input 108 is located outside a second beam path 124 of a second beam 126 of electromagnetic radiation that is defined by specular reflection 128 of the first beam 104 on the side wall 122. The mining machine 3 may also include a data port 40 to output relative position data of the mining machine 3 to the object 7 based on at least the determined range. The data port 40 may provide an output to a component of the mining machine 3 or a component external to the mining machine 3.

[0076] The mining machine 3, including the range finding system 100, advantageously avoids or reduces negative effects of specular reflection 128 of the first beam 104 that may dazzle the electromagnetic input 108, provide erroneous readings, reduce the effectiveness or lifespan of the electromagnetic input 108, and/or otherwise affect range determination of the range finding system 100.

[0077] In one example, the object 7 may be a feature of a rock face of a wall 12 of a mine site. In another example, the object 7 may be a reflector provided as a marker. The range finding system 100 may also allow determination of a direction (i.e. a relative bearing) between the mining machine 3 and the object position. Therefore, in one embodiment the relative position data may include the range and relative direction between the mining machine 3 and the object position of the object 7 (e g. defined with a polar coordinate system). It is to be appreciated that the relative position data may be expressed in other forms, such as in the Cartesian system.

[0078] The mining machine 3 may, with a processing device 9, determine a first position of the mining machine 3 based on the determined relative position data of the mining machine 3 to the object 7 and the object position of the object 7. In one example, the object position of the object 7 is known, and the known position may be retrieved from a data store 213. 12 2016200789 12 Oct 2016 [0079] The mining machine 3 may also include a first sensor system 5 to determine movement data of the mining machine 3 based on dead reckoning. In some examples, the first sensor system 5 may include accelerometers and gyroscopes to provide linear and angular acceleration (or alternatively displacement) data to allow determination of the movement data based on dead reckoning. This may include inertial navigation systems. The first sensor system 5 may include an odometer to determine distance travelled and compass (such as a digital compass based on an output of magnetometers) to determine the direction of the mining machine 3.

[0080] Referring to Fig. 1, the mining machine 3 may first determine a first position 30 with the range finding system 100. The mining machine 3 may then traverse along path 10. The first sensor system 5 may determine the movement data of the mining vehicle 3 based on dead reckoning of the relative displacement of the vehicle from the first position 30 along the path 10. The processing device 9 may then determine a second position of the mining machine 3 based on the first position 30 and the movement data of the mining machine 3 based on dead reckoning.

[0081] This allows the mining machine 3 to determine a second position 32 of the vehicle 3 after determination of a first position (that is based on determinations of the range finding system 100). It may also allow the mining machine to determine positions between subsequent position determinations based on subsequent outputs of relative position data (e.g. between range determinations from the range finding system 100).

[0082] The mining machine 3, determining position based on the relative position data, may determine position more accurately than with a system relying only on dead reckoning. The configuration of the mining machine 3 may be advantageous over other systems as the range finding system 100 may allow determination of relative position data without requiring positioning of expensive identifiers at reference positions. For example, known systems may include using radio-frequency identification technology (known as RFID) which requires prepositioning RFID tags at known positions. To provide position data to a vehicle, the vehicle may be equipped with a reader such that when the vehicle is in closer proximity, the reader may be able to read the RFID tag associated with the known position. Such known technology may incur costs such as labour to pre-position the RFID tags as well as the cost of the devices themselves. Furthermore some RFID tags are passive transponders which require 2016200789 12 Oct 2016 13 corresponding readers to be within an operational range. Other systems may be based on optical readers, such as a system of pre-positioned barcodes, whereby barcode scanners are used to determine the specific barcodes that are in proximity to the vehicle. However, dust and other obscurants may reduce the effectiveness of such systems. Known systems and methods include the subject matter of International publication WO 2005/003875 (SANDVIK TAMROCK OY).

[0083] The configuration of the mining machine 3 including the range finding system 100 may include one or more sealing elements 130 that, in conjunction with the side wall 122, seal the inside of the enclosure 120 from outside of the enclosure 120. This configuration may advantageously prevent ignition of gas outside the enclosure 120 by ignition triggers from the inside of the enclosure.

[0084] The mining machine 3 may be a continuous mining machine or a longwall mining machine.

Method of monitoring the position of a mining machine [0085] A method 9100 of monitoring a position of a mining machine 3 will now be described with reference to Fig. 3.

[0086] The method includes the step of receiving 9110, from the data port 40 in the mining machine 3, relative position data of the mining machine to the object 7.

[0087] The method may also include the step of determining 9112 a first position 30 of the mining machine 3 based on the received relative position data of the mining machine 3 to the object 7 and the object position. This may be shown in Fig. 1 as mining machine 3 in the first position 30. The method 9100 may also include the step of receiving 9114, from a data store 213, an object position data associated with the object 7 in the data store, wherein the step of determining 9112 the first position is further based on the received object position data associated with the object 7. In one example, the object position data may be indicative of an absolute position of the object 7. 14 2016200789 12 Oct 2016 [0088] The method further includes receiving 9120 an output of the first sensor system 5 that is indicative of movement data of the mining machine based on dead reckoning. This may occur as the mining machine 3 travel along the path 10 as shown in Fig. 1.

[0089] The method further includes determining 9130 a second position 32 of the mining machine 3 based on: the relative position data of the mining machine 3; and the movement data of the mining machine 3 based on dead reckoning. The second position 32 of the mining machine is shown in Fig. 1.

[0090] The step of determining 9130a second position may be further based on the first position 30 of the mining machine 3. For example, the second position may be determined by first determining the first position 30 and, based on the movement data along the path 10 from the first position 30 to the second position 32, determining the second position 32.

[0091] The step 9130 of determining the second position 32 of the mining machine 3 may be further based on a starting position data of the mining machine 3. The starting position data may be a known starting position for the mining machine 3, such as a pre-surveyed position in a mine.

Method for determining structural changes in a tunnel [0092] A method 9200 of determining structural changes in a tunnel 9251 will now be described with reference to Figs. 4, 5a and 5b.

[0093] Fig. 5a illustrates a vertical cross-sectional view of the tunnel 9251. The tunnel 9251 includes a roof 9253, side walls 9255, 9257, and floor 9259 as shown in solid lines. Fig. 5a also shows the tunnel 9251 with an exaggerated convergence behaviour that represents a structural change as shown by the dashed lines 9265. The dashed line 9265 shows deformation of the side walls 9255, 9257 and a general change in shape of the roof 9253. The floor 9259 may also change. It can be seen that the upper most comer 9261 is generally supported by the surrounding strata. On the other hand, side corner 9263 is deformed. This structural change may occur by reason of removing material from adjacent the upright wall 9257. Thus it can be seen that the profile of the tunnel 9251 has changed, which may represent a hazard for personnel and mining equipment. A convergence as shown in Fig. 5a 15 2016200789 12 Oct 2016 could be indicative of collapse of strata into mined coal (or other material). This convergence is a structural change of the surfaces of the tunnel 9251. Fig. 5b illustrates a mining machine 3 with a range finding system 100 traversing through the tunnel 9251.

[0094] The steps of the method 9200 will now be described.

[0095] The method 9200 includes the step of receiving 9210 a first profile scan of the tunnel 9251, wherein the first profile scan is based on the received plurality of relative position data. The first profile scan may be represented in a three-dimensional point cloud of the surroundings. Alternatively, the profile scan may be represented by a plurality of cross-sectional views, such as the vertical cross-sectional view in Fig. 5a. In one example, the first profile scan of the tunnel 9251 may provide a profile of the tunnel shown in solid lines of the roof 9253, side walls 9255, 9257, and floor 9259 (i.e. the tunnel 9251 without convergence behaviour).

[0096] The method 9200 also includes the step of storing 9220 the first profile scan in a data store 213 (discussed below).

[0097] The method 9200 includes subsequently receiving 9230 a second profile scan of the tunnel 9251, wherein the second profile scan is based on receiving a plurality of relative position data from the same mining machine 3 or different sensor system. As an example, the second profile scan of the tunnel 9251 occurs after convergence behaviour of the tunnel.

Thus the second profile scan may provide a profile as shown in dashed lines 9265.

[0098] The method 9200 further includes processing 9240 the first profile scan and the second profile scan to determine any structural changes on the surface of the tunnel corresponding to deformation in profile of the tunnel. Referring to Fig. 5a, it is clear that there are differences in the first and second profiles (which may be the differences between the solid lines of the roof 9253, side walls 9255, 9257, and floor 9259 compared to the dashed lines 0265.).

[0099] Advantageously the method 9200 may allow determination of structural changes, such as subsistence, which may be a maintenance or safety issue. It is to be appreciated that 16 2016200789 12 Oct 2016 the second profile scan (or one or more subsequent profile scans) may be stored in data store 213 which so that the step of processing 9240 may be performed at a later time.

[0100] In some examples, the profile scans may be stored to determine structural changes over time. Information derived from the profile scans may be used to allocate resources, such as maintenance resources, to the tunnel. It may also be used as part of a safety system to determine unsafe or potentially unsafe conditions.

[0101] In some examples, the method may be performed by distributed network elements. For example, a first mining machine 3 may traverse the tunnel 9251, whereby the first mining machine sends a first profile scan (or plurality of relative position data) to a data store. A second mining machine may, at a later time, traverse the tunnel 9251, whereby the second mining machine sends a second profile scan (or plurality of relative position data) to the or another data store. A processing device may then receive, from the or another data store, the first and second profile scan and determine any structural changes.

[0102] It is to be appreciated that the method may be modified. An example of methods of monitoring and determining structural change that may be used with the present mining machine 3 is disclosed in PCT/AU2005/001039 (COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION), published as WO 2007/009149, which is incorporated herein by reference.

Detailed description of components of the mining machine 3 [0103] Details of the mining machine 3 will now be described.

Types of minins machines 3 [0104] There are a wide variety of mining machines 3, the variety depending amongst other things, the type of mine, the materials, as well as the function of the mining machine 3 in the mine. Types of mining machines include longwall mining machines, continuous mining machines. Other mining machines include vehicles such as trucks, articulated trucks, loaders, dozers, etc.

Lonewall minins machines 17 2016200789 12 Oct 2016 [0105] A longwall mining is typically used for mining coal. Longwall mining may utilise one or more mining machines 3 such as a gateroad traversing structure 6309 or a shearer 6301 as discussed below.

[0106] Fig. 6 is a diagrammatic view showing a 3D cut-away of a longwall underground coal mining operation (not to scale). Here, there is a provided a longwall shearer 6301, that traverses from side to side across a coal panel 6303 in a coal seam 6305. At each side of the coal seam 6305 there are provided rectangular shaped roadways known as gateroads 6307.

The gateroads 6307 are cut into the strata and/or the coal seam 6305 so that the direction and size of the gateroads 6307 conforms to accurate parameters such as size and 3D positioning and direction. Typically, the gateroads 6307 run parallel to one another. A gateroad traversing structure 109 is provided in one or both of the gateroads 6307. Mechanical linkage 6311 connects the gateroad traversing structure 6309 and the shearer 6301. Typically, the mechanical linkage 6311 is a rail track means on which the shearer 6301 can traverse.

[0107] The gateroad traversing structures 6309 form part of the mining machine installation associated with mining, and the gateroad traversing structures 6309 assume a particular position of retreat in the gateroads 6307 during mining. The shearer 6301 traverses backwards and forwards along the rail track means forming the mechanical linkage 6311. As the shearer 6301 moves, coal is removed from the coal panel 6303. After the shearer 6301 has traversed from one side to the other side of the coal panel 6303, the gateroad traversing structures 6309 are caused to retreat in the direction of the arrows 6313, thereby bringing the shearer 6301 into a position to mine further coal from a fresh face of the coal panel 6303. The above process is repeated, advancing the face, until the coal seam 6305 is removed.

[0108] The gateroads 6307 may, at least initially, be in the form of tunnels. As discussed herein, tunnels 9251 located underground may be susceptible to convergence behaviour. Therefore in one example the gateroad traversing structures 6309, as a mining machine 3, may include a range finding system 100 as described herein. This may advantageously allow monitoring the position of the traversing structure 6309 in the method 9100 and/or facilitating the method 9200 of determining structural changes in a tunnel 9251 in a mining operation.

Continuous minim machine 18 2016200789 12 Oct 2016 [0109] A “room and pillar” system is another technique for mining that may be used for coal mining. This may involve removing coal from a coal seam that become the “rooms” whilst leaving parts (the “pillars”) of the coal seam in place to support the overlying roof material.

[0110] A typical machine used for the room and pillar system is a continuous miner, as shown in Fig. 7. The continuous miner 7301 includes a rotating drum 7303 with a plurality of cutting teeth 7305. The cutting teeth 7305 engages a wall of the coal seam to scrape away coal from a coal face of the coal seam. The broken coal at a front 7309 of the continuous miner 7301 may then be transported by a conveyor 7307 towards a rear 11 of the continuous miner 7301. The continuous miner 7301 may also have continuous tracks 7313 for mobility. Thus the continuous miner 7301 may scrape coal, transport the coal (via the conveyor) as well as manoeuvre itself.

[0111] The continuous miner 7301 may manoeuvre through rooms (which are considered tunnels) susceptible to converging behaviour. Therefore in one example, the continuous miner 7301 may be equipped with a laser range finding system 100 as described herein. This may advantageously allow monitoring the position of the continuous miner 7301 in the method 9100 and/or facilitating the method 9200 of determining structural changes in a room (such as a tunnel 9251) in a mining operation.

First sensor system 5 [0112] First sensor system 5 may include sensors to determine movement data of the mining machine 3. The first sensor system 5 may include sensors to determine movement data, which may include determining parameters such as linear and angular acceleration, speed (and/or velocity), displacement, and orientation. These parameter may, in turn be used to determine movement data, such as displacement of the mining machine (from a previous position) based on dead reckoning. It is to be appreciated that clock and time information may also be used to determine movement data.

[0113] Sensors may include accelerometers, gyroscopes, magnetometers, speedometers, odometers, etc. It is to be appreciated that outputs from other components of the mining machine 3 may also assist the first sensor system 5 to determine movement data based on 2016200789 12 Oct 2016 19 dead reckoning. For example the mining machine may provide an output indicative of a steering angle of the wheels, which may be used to determine a direction of movement.

[0114] In one example, the first sensor system 5 includes an inertial measurement unit to provide outputs on linear acceleration and angular velocity in one or more axes. The inertial measurement unit may also include sensors to output orientation information, such as from magnetometers. An example of an inertial measurement unit is offered by LORD MicroStrain under the trade mark 3DM-GX4-25, which includes triaxial accelerometer, triaxial gyroscope and triaxial magnetometers. The outputs from the inertial measurement unit may be combined with time information to determine movement data.

[0115] Another example of a first sensor system 5 may include a sensor to provide direction information (such as a magnetometer, or derived from a gyroscope). The sensor system may also include an odometer. Thus movement data may be determined by combining direction information and an odometer output.

Processing device, computer system and network [0116] Fig. 8a illustrates a schematic of linked systems in a mining machine 3. The mining machine 3 includes a processing device 9 that, in one example, is a computer system 205 (described in detail below). The range finding system 100 may output, via data port 40, relative position data to the computer system 205. The computer system 205 may also be in communication with the first sensor system 5 to receive movement data of the mining machine 3. Actuators 8201 of the mining machine 3, such as propulsion (e.g. powertrain) and steering systems may also be in communication with the computer system 205. A network interface 8203, such as a wireless communication network interface, is provided to facilitate communication between the mining machine 3 and a network 8205.

[0117] An example of the computer system 205 (as shown in Fig. 15) includes a processor 209 connected to a program memory 211, data store 213 and the communication port 207.

The program memory 211 is a non-transitory computer readable medium, such as a hard drive, a solid state disk or CD-ROM. 20 2016200789 12 Oct 2016 [0118] Software, that is an executable program, stored on program memory 211 causes the processor 209 to perform the tasks, such as determining the first and second position of the mining machine 3 based on the relative position data, movement data, or object position.

[0119] The processor 209 may store, in a data store 213, the relative position data (including the determined range 114), movement data, profile scan data, environmental conditions, time and date, object position (such as the absolute position of an object), other information associated with the object (e.g. surface profile of the object) etc. The information in the data store 213 may be retrieved for analysis at a later time.

[0120] Referring to Fig. 8b, the mining machine 3 may be in communication with a communications network 8205. Other network elements may include a monitoring device 8207 and a network data store 8209 that are in communications with the mining machines 3 via the network 8205. It is to be appreciated that Fig. 8b is an illustrative example only and other configurations of the network elements may be used. Furthermore, the mining vehicle 3 may have more than one computer system 205 and/or components thereof.

[0121] The mining machine(s) 3 may send, via the communications network 8205, data derived from the range finding system 100, the first sensor system 5 and/or other information from the computer system 205. The mining machine(s) 3 may also receive, via the communications network 8205, data from the monitoring device 8207 and/or the network data store 8209. Advantageously, the communications network 8205 may allow sharing of data from one of the network elements. As an example, the method of determining structural change 9200 may be performed by the monitoring device 8207 based on first and second profile scans from one or more mining machine(s). This may improve detection of structural changes if, for example, a route is frequently used by a large number of mining machines but where each mining machine may infrequently using the same route.

Ranse findins system 100 [0122] The range finding system 100 may provide relative position data based on determined range to an object 7. The range finding system 100 may also provide directional information to the object 7. The range and direction to the object may then be used to derive the relative position data between the mining machine 3 and the object 7. As noted above, the 21 2016200789 12 Oct 2016 range finding system 100 may be used to detect objects 7 such as walls 12 of a mine. This may be important during operation of the mining machine (3) in the mine to facilitate navigation of the mining machine (3) and to avoid inadvertent collisions with the walls 12 and/or other mining equipment.

[0123] In one embodiment, the range finding system 100 in the mining machine 3 may perform simultaneous localisation and mapping (SLAM) of the surrounding environment This may allow the mining machine 3 to “build a map” of an unknown surrounding environment.

[0124] The range finding system 100 may also be used to detect other objects 7 in the surroundings, include other mining machines 3 or even component of the mining machine itself. For example, in longwall mining the mechanical linkages 6311, such as rail track, need to be moved as the gateroad traversing structures 6309 are caused to retreat. The rail track may need to be positioned at specified positions to ensure optimum efficiency of mining. Therefore, in one embodiment the laser range finding system 100 may be used to determine the position of at least part of the mechanical linkages 6311. This may be a relative and/or absolute position of the mechanical linkages 6311. The determined position may then be used to determine if the mechanical linkages 6311 need to be moved towards the specified position(s).

[0125] An embodiment of the range finding system 100 will now be generally described with reference to Figs. 2 and 9.

[0126] Fig. 1 is a simplified view of a range finding system 100 provided at a mining machine 3 to determine range information with respect to an environment 1. The environment 1 includes objects 7’, 7”, 7”’ that are within line of sight of the range finding system 100. The range finding system 100 can be steered to direction A to determine a first range 15 between the mining machine 3 and the first object 7’, whereby first object 7’ is in direction A relative to the mining machine 3. Similarly, the range finding system 100 can be steered to determine a second range 17 in direction B to the second object 7”. Multiple range determinations may also be made on one object, as illustrated by third and fourth ranges 18 and 19 in directions C and D on the third object 7”’. Multiple range determinations may be made in multiple directions and the range information combined to provide contour 2016200789 12 Oct 2016 22 information of the environment, such as in a three-dimensional point cloud. In one example application, the object 7”’ is a coal face in an underground coal mine. Providing contour information, that is mapping the surface of the coal face, using the range finder disclosed herein has the advantage that less personnel enters unsupported parts of the mine and machinery can be controlled more efficiently.

[0127] With reference to Fig. 2, the range finding system 100 further includes a first support element 132 rotatable within the enclosure 120 around a first rotation axis 134. The electromagnetic output 102 is supported by the first support element 132 such that rotation of the first support element 132 steers the first beam 104 provided by the electromagnetic output 102. This allows the range finding system 100 to steer the first beam 104 for determining ranges in a plurality of directions. A second support element 140 is provided between the electromagnetic output 102 and the first support element 132, and the second support element 140 is rotatable around a second rotation axis 142 to provide a further degree of freedom for steering the first beam 104. In the illustrated embodiment, the configuration avoids the specular reflection 128 of the first beam from dazzling the input 108 throughout a 360 degree rotation of the first support element 132 around the first rotation axis 134.

[0128] The components of the range finding system 100 will now be discussed in detail.

First and second support elements [0129] The first and second support elements 132, 140 will now be described with reference to Figs. 10 to 12. The first support element 132 rotatably supports the second support element 140. The second support element 140, in turn, rotatably supports the electromagnetic output 102 and the electromagnetic input 108.

[0130] The first support element 132 is rotatable around the first rotation axis 134, to provide azimuth direction φ for steering electromagnetic output 102 and electromagnetic input 108. In one embodiment, the first support element 132 is rotatable around a full 360 degrees to allow the range finding system 100 to take a plurality of range measurements for scanning the surrounding environment. 23 2016200789 12 Oct 2016 [0131] The first support element 132 is operatively coupled to an actuator 203 (as shown in Fig. 8) to rotate the first support element 132, along with the supported second support element 140, electromagnetic output 102 and electromagnetic input 108. In one form, the actuator is a motor, such a stepper motor that receives actuation inputs from a controller module 201. The actuator may operate to actuate the first support element 132 directly, such as a direct drive, or indirectly, such as through a gear mechanism or a belt drive. In one form, the gear mechanism or belt drive provides a reduction in rotational speed of the drive to allow greater accuracy in movement of the first support element 132.

[0132] The second support element 140 is rotatable around the second rotation axis 142, different to the first rotation axis 134, to provide a further degree of freedom to the supported electromagnetic output 102 and input 108. The second support element 140 supports the electromagnetic output 102 offset from the first rotation axis 134 so that the first beam path from the output 102 to the side wall 122 does not intersect the first rotation axis 134. This configuration, along with the coaxial first rotation axis and centre axis 136 provides a beam path 106 that has an angle of incidence with the cylindrical side wall 122 that is neither at nor close to zero degrees. In other words, the beam path 106 is not along the surface normal 111 of the cylindrical side wall 122, as illustrated in Fig. 12. As a result, the specular reflection 128 of the first beam 104 on the cylindrical side wall 122 provides a second beam 126 having a second beam path 124 that is directed away from the electromagnetic output 102, and more importantly, away from the electromagnetic input 108 that is located proximal to the electromagnetic output 102.

[0133] Furthermore, the beam path 106 may preferably have an angle of incidence with the cylindrical side wall 122 that is neither at nor close to 90 degrees. A large angle may cause a significant specular reflection of the electromagnetic radiation, thereby reducing the electromagnetic radiation 110 that would be received by the electromagnetic input 108.

[0134] In one form, the electromagnetic output 102 is supported by the second support element 140 such that the first beam 104 provided by the electromagnetic output 102 is substantially perpendicular to the second rotation axis 142.

[0135] In one embodiment, the second rotation axis 142 is perpendicular to the first rotation axis 134. The second support element 140 provides adjustment in elevation Θ of the 24 2016200789 12 Oct 2016 electromagnetic output 102 and input 108 relative to a horizontal plane 138 that is perpendicular to the first rotation axis 134. The movement of the second support element 140 may be by an actuator 203 such as those discussed above.

[0136] The first 132 and second 140 support elements, by being rotatable around different axes 134, 142 allow steering of the first beam 104 of electromagnetic radiation. It is to be appreciated that in other embodiments, the second rotation axis 142 does not need to be perpendicular to the first rotation axis 134 to provide the additional degree of freedom. However, the perpendicular arrangement of these rotation axes may assist ease of control and calculation of the direction of the first beam 104.

Electromagnetic output and electromagnetic input [0137] The electromagnetic output 102 and electromagnetic input 108 are operable to provide time-of-flight information to allow determination of range. In one form, the electromagnetic output 102 and input 108 are substantially co-located (or adjacent to each other) with the output 102 and input 108 directed by the first and second support elements 132, 140 in the same direction. Usually, this involves directing the electromagnetic output 102 and input 108 towards the object7, although some variations may be included to take into account refraction, displacement, or other alignment considerations which will be discussed in detail below.

[0138] In one form, the electromagnetic output 102 and input 108 are in the form of a laser range finder. Thus the electromagnetic output 102 may be in the form of a laser emitter that emits one or more pulses of laser light for the first beam 104. The electromagnetic input 108 may be in the form of a light sensor that is sensitive to the laser light. An example of a laser emitter may include a laser diode. The wavelength of laser light may include, 850nm, 905nm, 1535nm. In one form the power output of the laser light is controlled to ensure the laser output meets safety requirements such as being an eye safe laser and/or to prevent the laser light becoming an ignition trigger. In one form, the combined power of the laser and other components in the enclosure 120 (such as motors, actuators, light sensor, controller, radio communication modules etc) is less than 6W. In one embodiment the effective radiated power (9 kHz to 60 GHz ) from the apparatus is preferably not more than 10 W, more preferably no more than 6 W and even more preferably no more than 4 W. The laser 2016200789 12 Oct 2016 25 preferably has an effective radiated power of no more than 1W and more preferably no more than 150mW. In a particular embodiment, the apparatus conforms to the effective radiated power (9 kHz to 60 GHz) of IEC 60079-0:2011, preferably for Group I gases (e.g. for coal mining environments).

[0139] To provide a range determination, a pulse of laser light (in the first beam 104) is provided by the electromagnetic output 102 that travels through the side wall 122 of the enclosure 120 and towards the object7. The light is reflected off the object 122, and at least some of the reflected laser light 110 travels back towards the range finding system 100, passing through the side wall 122 to be received by the electromagnetic input 108. The time of flight between output 102 of the pulse of light to receiving the input of the reflection is used to determine range. For a system 100 where the output 102 is located near the input 108, range, or at least an approximation thereof, may be determined by the following equation:

Range = (Time of flight)x(Speed of light through the medium) 2 (Equation 1) [0140] It is to be appreciated that this equation may be varied to take into account known variables and constants. For example, the laser light of the first beam 104 travelling through the enclosure 102 may travel at a speed less than the speed of light through air. A variation may include calculating the time delay for the pulse of light travelling through the side wall 122. In one form, the average thickness of the side wall 122 may be used. In another form, the distance that the beam 104 has to travel through the enclosure at the given orientation of the electromagnetic output 102 may be used. In another example, there may be delays in the response time of one or more of the components. This may be taken into account by modification of Equation 1 or through calibration of the system 100.

[0141] In one form the electromagnetic output 102 and electromagnetic input 108 are housed inside a casing (not shown). The casing, along with the electromagnetic output 102 and electromagnetic input 108 housed within, is supported by the second support element 140. Therefore when the first 132 and second 140 support elements are rotated, the casing (with the output 102 and input 108) is also rotated. The casing is sealed to reduce dust contamination. In a further embodiment, the casing is sealed to reduce the risk of ignition triggers inside the casing from igniting gas (or other combustible material) outside of the 26 2016200789 12 Oct 2016 casing. This provides a further layer of safety in addition to that provided by the sealed enclosure 120. In another form, the casing may also include a filter covering the electromagnetic input 108 that allows transmission of the wavelength of the reflected electromagnetic radiation 110, but absorbs or reflects one or more other wavelengths.

[0142] An example of a laser range finding system 100 may include a commercially available laser range finder, or components thereof. An example of a laser range finder unit includes one offered by Hokuyo Automatic Co. Ltd with the model number UTM-30LX.

This laser range finder unit includes an electromagnetic output 102 of laser light having a wavelength of 905 nm and an electromagnetic input 108 that is steered to provide a horizontal scanning range of 270 degrees. This laser range finder unit has a universal serial bus interface for interfacing with the controller module 201.

[0143] In the above mentioned example, the electromagnetic output 102 includes a laser range finder that outputs electromagnetic radiation in the infrared spectrum. However, it is to be appreciated that other wavelengths may be used, including electromagnetic radiation in the visible light spectrum and/or ultraviolet spectrum. Furthermore, in some alternatives, other wavelengths in the electromagnetic spectrum may be suitable.

Enclosure [0144] In the embodiment shown in Fig. 2 , the enclosure includes the side wall 122 and a sealing element 130, in the form of a circular cover 133, that is received at the a top portion of the side wall 122. A further sealing element 130, in the form of a base (not shown), is provided to interface with the bottom portion of the cylindrical side wall 122. The base may be part of (or an extension of) a body of the mining machine 3.

[0145] In the illustrated embodiment, the side wall 122 is a curved side wall that extends around the central axis 136 to form a cylindrical side wall. In this embodiment, the wall extends for 360 degrees around the central axis 136. This facilitates the range finding system 100, in particular the electromagnetic output 102 and input 108 mounted on the first support element 132, to scan in a plurality of directions. In one embodiment, this allows the first support element 132 to rotate and scan a full 360 degrees around the range finding system 100. 27 2016200789 12 Oct 2016 [0146] In one embodiment the first rotation axis 134 is coaxial with the central axis 136 of the cylindrical side wall 122. This arrangement can allow simplified calculation and/or calibration of the range finding system 100. In particular, it can simplify calculation (and/or calibration) of changes in direction, or displacement, of the first beam 104 as the beam passes through the cylindrical side wall 122, because the angle between the first beam 104 and the surface normal 111 is independent of the azimuth direction φ.

[0147] In an alternative forms, the side wall 122 may include more than one single curved surface or facet, and may be of other shapes. Figs. 17(a) to (d) illustrate alternative forms of enclosures 120. Fig. 17(a) illustrates an enclosure with curved side wall 122 that is, at least in part, the curved side wall resembling the surface of a cone. Fig. 17(b) illustrates a multifaceted side wall 122 resembling a hexagonal prism. Fig. 17(c) illustrates yet another alternative enclosure 120 having planar side walls 122 to form an enclosure that resembles a square pyramid. Fig. 17(d) illustrates another embodiment where the enclosure 120 includes ahemi-spherical sidewall 122.

[0148] As noted above, the configuration of the sealing elements 130 and the cylindrical side walls 122 seal the inside of the enclosure 120 from the outside of the enclosure 120. In one form, the seal is a hermetic seal that prevents or substantially prevents gasses from transferring between the inside and outside of the enclosure 120. The hermetic seal prevents or reduces the risk of an ignition trigger, such as an electrical spark, inside the enclosure 120 from propagating and causing an ignition of gas outside of the enclosure 120. This is advantageous when the range finding system 100 is used in an environment with combustible fuels such as hydrocarbon gas (such as methane), coal dust, etc. that can be found in underground mines.

[0149] It is to be appreciated that in other embodiments, the seal formed by the sealing elements 130 with the cylindrical side walls 122 may not be a perfect hermetic seal. In one form a close fit between the sealing 130 and the cylindrical side walls 122 may provide a sufficient barrier to prevent propagation of a flame or other ignition triggers from inside of the enclosure 120 to outside of the enclosure 120. In one example, one or more gaps may exist between the cylindrical side walls 122 and the sealing elements 130. Alternatively, the cylindrical side walls 122 and/or the sealing elements 130 may include one or more gaps. In one form, the one or more gaps, and the enclosure 120 in general, are compliant with 28 2016200789 12 Oct 2016 requirements for construction of flameproof enclosures such as IEC 60079-0 Ed. 6.0 b :2011 and IEC 60079-1 Ed. 7.0 b:2014, or one or more of the other standards discussed herein.

[0150] In the illustrated embodiment, the sealing elements 130 are removably attached with the cylindrical side wall 122. This allows access and servicing of parts, such as the electromagnetic output 102 and electromagnetic input 108, within the enclosure 120. In another embodiment, the sealing elements 130 may be permanently attached to the cylindrical side wall 122 to maintain integrity of the seal, and/or prevent or reduce the potential for tampering of the enclosure 120 and components therein. In yet another embodiment, one or more of the sealing elements 130, such as the circular cover 133 or base 134, may be integrally formed with the circular side wall 122.

[0151] In some embodiments the sealing elements 130 are, at least in part, formed of steel or engineering grade plastic. The sealing elements 130 may be formed of a material, or covered with a material, that is non-r effective or substantially non-reflective to the wavelength of the electromagnetic radiation from the electromagnetic output 102. This reduces opportunity and/or the intensity for the electromagnetic radiation from the electromagnetic output 102 from reflecting multiple times within the enclosure 120 that could be received by the electromagnetic input 108.

[0152] The side wall 122 of the enclosure 120 is made of a material selected to be substantially transparent to allow transmission of the wavelength of the electromagnetic radiation from the electromagnetic output 102. In one example, the material includes a glass that is transparent to the wavelength of light produced by a laser emitter. Transparent in this context means that there may be some attenuation of the radiation but the intensity of the transmitted radiation is sufficient to allow sensing of the radiation reflected from the object.

[0153] The material of the cylindrical side wall 122 may be transparent to wavelengths other than that of the electromagnetic output 102. In one embodiment, it may be desirable to exclude these other wavelengths from being received by the electromagnetic input 108. This may include providing a coating on the cylindrical side wall 122 that reflects the other wavelengths to prevent such electromagnetic radiation, outside of the enclosure 120, from entering into the enclosure 120 and being received by the electromagnetic input 108. Alternatively, the cylindrical side wall 122 may be provided with a coating to absorb such 29 2016200789 12 Oct 2016 other wavelengths. In another embodiment, the enclosure may be constructed of a material that is inherently opaque to one or more of the other wavelengths. In yet another embodiment a filter may be provided, either outside of the enclosure, or inside of the enclosure, to filter out or reduce the intensity of such other wavelengths from being received by the electromagnetic input 108.

[0154] In one example of the range finding system 100, the cylindrical side wall 122 is formed of toughened glass with a thickness of approximately 10mm. The internal diameter of the cylindrical side wall 122 has a radius of 150mm. This example includes an electromagnetic output 102 that is offset by 30mm from the first rotation axis 134 (and the central axis 136), and with the electromagnetic output 102 providing a first beam 104 in a direction substantially perpendicular to the second rotation axis 142. These dimensions provide a first beam 104 that is incident on the side wall 122 at an angle away from the surface normal 111. Preferably the surfaces of the side wall 122 should be as smooth and consistent to prevent or reduce distortions in the beams.

[0155] The side wall preferably possesses the following optical properties, in reference to the operating wavelength(s) of the range finding system: • The internal surface of the side wall has a specular reflection (measured at an incident angle of 5 degrees) of preferably no more than 10%, more preferably no more than 5% and even more preferably no more than 2% and yet even more preferably no more than 1%; and • The transparency of the side wall (measured at an incident angle of 5 degrees) is such that there is at least 90% transmission, more preferably 95% transmission and even more preferably 98% transmission of the operating wavelength(s).

[0156] A combination of low internal reflection and high transmission promote excellent range finder performance and reliability. Low internal reflection may be achieved through use of an anti-reflective coating, such as Claryl™ available from DSM (Netherlands).

[0157] The transparency of the side wall 122 may allow the first beam to pass through the side wall 122 at multiple locations (and directions) as the first beam is steered on rotation of 30 2016200789 12 Oct 2016 the first support element (132) and the second support element (140). This may be in contrast to a side wall 122 having an aperture (or window) that may only allow the first beam to pass through at a particular localised location (i.e. at the aperture) at the side wall, which may limit the ability to steer the first beam.

Controller module, computer system and display [0158] Figure 15 illustrates an embodiment of the range finding system 100 further including a controller module 201 to provide inputs to actuators 203 for operatively moving the first and second support elements 132, 140 to steer the first beam 104 of the electromagnetic output 102. This allows a plurality of range determinations of one or more objects 7 in the surrounding environment. The controller module 201 is also interfaced with the electromagnetic output 102 to control the generation the first beam 104, such as providing a command to operatively generate a pulse of laser light. Furthermore, the controller module 201 is interfaced with the electromagnetic input 108 to receive information from the electromagnetic input 108, such as information from a light sensor. In one form the controller 201 includes a timing module (not shown) for determining the time of flight, based on the time difference from the pulse of the laser light travelling from the electromagnetic output 102 to the time the reflected light 110 is received by the electromagnetic input 108. In one form the timing module comprises an oscillating quartz and the controller counts the number of oscillations between generating the pulse of laser light and receiving a signal from the light sensor. The controller then multiplies the counted number by a constant to determine the range. For example, the oscillation frequency may be 256 MHz, which results in a resolution factor of 1.17m.

[0159] In one form, the controller module is an ATmega640 microcontroller produced by Atmel.

[0160] A computer system may be in communication with the controller module 201 through the communication port 207. The computer system may be the computer system 205 as described above, or an additional computer system.

[0161] In the computer system, software stored on program memory 211 may cause the processor 209 to perform the tasks, such as determining the distance of the an object 7 to the 31 2016200789 12 Oct 2016 range finding system 100 (and hence the mining machine 3), the relative orientation of that object 7 to the range finding system 100, the relative position of the object and/or the absolute position of one or more points on the surface of that object 7. Such information can be determined based on receiving time-of-flight information from the controller module 201 and information relating to the orientation of the electromagnetic input 102, the steered beam 104, and/or the control inputs to the actuators 203.

[0162] Additional tasks may include the processor 209 directing the controller module 201 to perform scans (by multiple range determinations) on selected areas at selected times. This may include specific instructions to operate the actuators 203 and the electromagnetic output 102.

[0163] The processor 209 may then store in a data store 213 the distance of the object 7 to the range finding system 100, and other information, such as position of the range finding system, environmental conditions, the time and date, time-of-flight information of the pulse of the beam, information to determine the orientation of the electromagnetic output 102 and input 108, and the position of the mining machine 3. The information in the data store 213 can be retrieved for analysis or mapping of the environment surrounding the range finding system 100.

[0164] In a further embodiment the processor may perform a method of generating a representation of the surrounding environment in three dimensions based on the plurality of range determinations and the corresponding directions of the range determinations. In one form the representation is stored in the data store 213. In yet another embodiment, the representation of the surrounding environment is visually represented to a user on a visual display 216. This may include a three-dimensional point cloud.

Operation of the range finding system to avoid specular reflection interfering with the second input [0165] The operation of an embodiment of the range finding system 100 will now be described. The range finding system 100 is operable to provide scanning of the objects around the range finding system 100 in a full 360 degree arc around the central axis 136. This is achieved by rotating the first support element 132 around the first rotation axis 134 to a 32 2016200789 12 Oct 2016 selected azimuth φ. The range finding system 100 is also operable to make range determinations in various elevations Θ by rotating the second support element 140 around the second rotation axis 142. This is illustrated in an embodiment shown in Figs. 16(a) to (c) that illustrates the range of elevations for the first beam 104, including elevations approximately +/- 40 degrees from the horizontal plane 138. However it is to be appreciated that other embodiments may include steering in elevation more, or less, than 40 degrees from the horizontal.

[0166] Therefore during use, the range finding system 100 directs the beam in multiple directions, which must be transmitted through the enclosure 120 at multiple respective locations. Advantageously, the range finding system 100 directs the first beam 104 to the side wall 122 in a way that avoids specular reflection 128 of the first beam 104 from dazzling the electromagnetic input 108.

[0167] Referring to Figs. 11 and 12, this is achieved by directing the first beam 104 from the electromagnetic output 102 to be incident on the side wall 122 at an angle that is substantially away from the surface normal 111. Asa result, the specular reflection 128 of the first beam 104, shown as second beam 126 along the second beam path 124, is directed away from the electromagnetic input 108 (and the proximally located electromagnetic output 102).

[0168] In the embodiment shown in Figs. 11 and 12, the incident angle of the first beam 104 to the side wall 122 is always away from the surface normal 111, regardless of the azimuth direction (from rotation of the first support element 132 around the first rotation axis 134), or the elevation angle (from rotation of the second support element 140 around the second rotation axis 142). This is achieved by providing the electromagnetic output 102 (and the corresponding first beam path 106) that is offset from the common first rotation axis 134 and central axis 136 of a substantially cylindrical side wall 122.

[0169] With respect to the above embodiment, it is to be appreciated that a first beam 104 that is incident at a side wall 122 at an angle close to but not exactly at the surface normal 111 can still provide specular reflection that can affect the electromagnetic input 108. For example, a first beam 104 with an angle of incidence of 1 or 2 degrees to the side wall 111 may reflect a substantial amount of electromagnetic radiation back towards the electromagnetic output 102 and the proximally located electromagnetic input 108. Therefore, 33 2016200789 12 Oct 2016 in some embodiments, it is desirable to have an angle of incidence of the first beam 104 to the side wall 122 that is greater than 5 degrees. In another embodiment, the angle of incidence is at least 10 degrees. In yet another embodiment, the angle of incidence is at least 12 degrees, or at least 15 degrees, or at least 20 degrees. A larger angle of incidence may be advantageous to reduce the electromagnetic radiation of the second beam 126 from affecting the electromagnetic input 108 by causing the second beam 126 to be reflected away from the electromagnetic output 102 and the collocated electromagnetic input 108.

[0170] In one embodiment, the first support element 132, along with the other supported components of the range finding system 100 are rotated at approximately 0.25 revolutions a second. The second support element 140, along with the supported electromagnetic output 102 and electromagnetic input 108, may be rotated at approximately 40 revolutions a second. Continuous rotation of the support element s 132, 140 allows the range finding system 100 to make a plurality of range determinations. It is to be appreciated that other rotation speeds may be used.

[0171] In one embodiment the first support element 132 and second support element 140 are rotatable to 360 degrees or more around the respective axes. This allows range determination of a point on an object7 from two or more configurations of the electromagnetic output 102. This allows redundant measurements, or stereo measurement of range of the surface of the object, or the environment. This is illustrated in Fig. 20 where a first configuration of the electromagnetic output 3102’ provides a corresponding first beam 3104’ towards a point 3112 on the object7. The reflected electromagnetic radiation (not shown for clarity) is then received by the electromagnetic input 3108’. The electromagnetic output and input can then be moved into a second configuration by movement of the support elements. In the second configuration, the electromagnetic output 3102” provides a corresponding first beam 3104” towards the same point 3112 on the object. The reflected radiation is then received by the electromagnetic input 3102”.

[0172] The above described example is one solution, and it is to be appreciated that in other embodiments, a different configuration may be used to provide a first beam 104 that is not incident on the side wall 122 at an angle that causes a specular reflection 128, being the second beam 126 that is directed towards the electromagnetic input 108. For example, in one alternative the electromagnetic output 102 is a first reflector (e.g. a mirror or prism) that 34 2016200789 12 Oct 2016 redirects the laser light from a laser emitter to provide the first beam 104 on the first beam path 106. In a further embodiment, the electromagnetic input 108 includes a second reflector that redirects the reflected laser light 110 to one or more light sensors. In this embodiment, the one or more first and second reflectors function to provide an offset for the laser emitter and/or light sensor to prevent the second beam 124 from dazzling the light sensor. Examples of these alternatives are described below.

[0173] It is to be appreciated that other arrangements, in addition to the specific examples described herein, may achieve the result of the second electromagnetic input (108) to be located outside a second beam path (124) of a second beam (126) of the electromagnetic radiation. Such other arrangements may be designed by specifying multiple first beam paths (106) from the electromagnetic output (102) that may be used during function of the range finding system (100). From this, respective multiple second beam paths (124) may be calculated based on specular reflection from the first beam paths (106). A designer may then design the range finding system (100) such the electromagnetic input (108) is located outside each of the second beam paths (124) when the range finding system (100) is configured for the electromagnetic output (102) to provide each of the respective first beams (104)

Refraction of the first beam passing through the side wall [0174] As noted above, a substantially cylindrical side wall 122 assists the calculation and/or calibration of the range finding system 100. Fig. 13 shows a top view of the electromagnetic output in three positions, 1102’, 1102”, 1102’” around the first rotation axis 134 at various azimuth angles φ’ (which is zero and not shown) φ” and φ”\ As the first beam 1104’, 1104”, 1104”’ passes through the cylindrical side wall 122 the different refractive index of the air (within the enclosure 120 and outside the enclosure 120) compared to the refractive index of the material of the cylindrical side wall 122 causes refraction of the first beam 1104’, 1104” and 1104”’. This alters the path of the first beam, which may include a change in direction and/or causing the path of the first beam to be displaced. In Fig. 13 this is illustrated by the first beam 1104’, 1104” and 1104’” that is incident on the cylindrical side wall 122. The path of the transmitted first beam 1104A’, 1104A” and 1104A’” is altered as illustrated in Fig. 13 by angle a from the respective original beam path 1106’, 1106” and 1106’”. Since the first rotation axis 134 and the central axis 136 are coaxial and that the cylindrical side wall 122 is substantially cylindrical, the alteration of the 35 2016200789 12 Oct 2016 path of the first beam 1104, at least in the components of the path in the directions perpendicular to the central axis 134, are substantially constant. That is, the alteration to the transmitted path of the first beam 1104A’, 1104A”, and 1104A’” is substantially the same (as illustrated by angle a) for all azimuth directions φ around the central axis 136 as shown in Fig. 6.

[0175] It is to be appreciated that the alteration to the path shown by angle a is not exclusive and that, depending on the properties of the material and physical configuration, the alteration to the first beam path could include a displacement in the beam. In yet another alternative, the transmitted first beam 1104A’, 1104A” and 1104A’” may have a path that is displaced and directed towards a different direction compared to the incident beam 104’, 104” and 104”’.

It will be appreciated that the path of the reflected radiation 110 that passes through the side wall 122 and is received by the electromagnetic input 108 can be calculated (and/or calibrated) with similar principles to that described for the first beam 1104.

[0176] For clarity in this description, only the alteration of the beam path for components in the directions perpendicular to central axis 136 are described in Fig. 6. The alteration of the path of the first beam 104 due to the relative elevation Θ of the electromagnetic output 102 will now be described with reference to Figs. 14(a) to 14(c).

[0177] Fig. 14(a) illustrates an electromagnetic output 2102 orientated at an elevation of 0 degrees such that the first beam 2104’ is substantially parallel to the plane 138 perpendicular to the central axis 136. In this orientation, the transmitted first beam 2104B’ is, with respect to the elevation component, substantially parallel and coaxial to the first beam 2104’ since refraction in the elevation component is substantially zero.

[0178] Fig. 14(b) illustrates the electromagnetic output 2102” orientated at an intermediate elevation of Θ” above the plane 138 perpendicular to the central axis 136. In this configuration the transmitted first beam 2104B” has an altered path relative to the first beam 2104” as the elevation of the electromagnetic output causes the first beam 2104” to be incident on the cylindrical side wall 122 at an incidence angle greater than zero degrees, resulting in refraction of the first beam in the elevation component. The deviation of the transmitted first beam 2104B” and the first beam 2104” is shown as displacement β”. 2016200789 12 Oct 2016 36

However, it is to be appreciated that the deviation is not limited to displacement but may, alternatively or in conjunction, be a change of direction of the beam path as discussed above.

[0179] Fig. 14(c) illustrates the electromagnetic output 2102’” orientated at a high elevation of θ’” above the plane 138 perpendicular to the central axis 136. In this configuration the transmitted first beam 2104B’” has a greater altered path relative to the first beam 2104”’ as the higher elevation of the electromagnetic output causes a greater angle of incidence resulting in greater refraction and consequent displacement of the first beam in the elevation component. The deviation of the transmitted first beam 2104B’” and the first beam 2104’” is shown as displacement β”’. In this embodiment, β” ’ is greater than β” and the displacement β increases as the elevation angle Θ increases.

[0180] In one form, the calculation of the alteration of the path of the first beam, including a and β, may be calculated with Snell’s law (Equation 2) together with the relevant refractive indexes. sin#! _ vt sin θζ v2 nz ni (Equation 2) where Θ is the angle of the path of light measured from the surface normal of the boundary between medium 1 and 2, v is the velocity of light in the respective medium, and n is the refractive index of the respective medium.

[0181] In one form, the configuration of the electromagnetic output 102 is provided to avoid total internal reflection of the first beam 104 when the first beam is incident on the cylindrical side wall 122. This configuration may include providing the first and second support elements 132, 130 such that the electromagnetic output 102 would not be orientated to provide a first beam 104 that has an incidence angle above a critical angle of the air to side wall, or side wall to air, boundary. 37 2016200789 12 Oct 2016

Variations and alternatives of the range finding system [0182] Further variations and alternatives of the range finding system 100 will now be described.

Shielding the electromagnetic input [0183] Figs. 18(a) and (b) illustrate an embodiment of the electromagnetic input 108, having a light sensor 310 that is shielded by a hood 312. The hood 312, in one embodiment, is in the form of a hollow tube forming a passage 314. In use, the hood 312 is movable with the other parts of the electromagnetic input 108 so that the passage is generally directed towards the object7 that the range finding system 100 is ranging. The passage allows the reflected electromagnetic radiation 110 from the object7 to pass through the hood 312 to be detected by the light sensor 310. Conversely, the hood blocks electromagnetic radiation from alternative directions, such as second beam 316 or third and subsequent beams 318 to be directly received by the light sensor 310. This may be advantageous to prevent the second beam 316 reflecting multiple times off the side wall 122 from being directly received by the light sensor 310. In addition, the hood 312 may shield the light sensor 310 from other sources of electromagnetic radiation that may affect the sensor 310, such as lights (for illumination), light from the sun, electromagnetic radiation from multi-path of the reflected electromagnetic radiation, or electromagnetic radiation other range finding equipment operating in the area.

[0184] In one embodiment, the hood 312 may include anti-reflective surfaces. Anti-glare baffles 320 may be included to shield the light sensor 310 as shown in Fig. 18(b).

Dust contamination test [0185] In use, dust or other contaminants may adhere to the enclosure 120 that may reduce the performance and effectiveness of the range finding device 100. For example, dust on the exterior of the enclosure 120 or inside the enclosure may attenuate, or otherwise disrupt the first beam 104 and/or the reflected electromagnetic radiation 110. This may reduce the effective range of the range finding device or at worst, prevent range determination altogether.

[0186] In some embodiments the dust is a combustible dust, such as coal dust or soot. In such circumstances, an increase in dust levels either inside or outside the enclosure may 2016200789 12 Oct 2016 38 reflect an elevated safety risk. Periodic maintenance inspection of the enclosure may be used to ensure dust levels do not reach elevated levels which may detrimentally impact apparatus performance or heighten safety risks.

[0187] In one embodiment, the range finding device 100 includes means to determine the level of contamination and performance of the range finding device 100. Preferably, the range finder triggers an alert or shuts down the device if the contamination levels exceed a predetermined amount. In one embodiment, this predetermined amount corresponds to contamination levels having elevated level of ignition risk. Referring to Fig. 19(a), the range finding device 100 includes a reflector 351 with a reflective surface 353 provided outside of the enclosure 120. The reflector 351 provides a reflective surface 353, with a known reflectivity, to provide a test (or calibration) surface. The reflector 351 may be mounted on the body of the mining machine 3.

[0188] In one form, a contamination test includes the range finding system 100 providing a first beam 104 that passes through the side wall 122, and is reflected off the reflective surface 353, and the reflected electromagnetic radiation 110 passing through the side wall 122 to be received by the electromagnetic input 108. The intensity of the received electromagnetic radiation 110 can be compared to past intensities of reflected electromagnetic radiation 110 reflected from the reflective surface 353. A reduction in the intensity can be indicative of degraded performance, such as dust contaminating the outside of the side wall 122, inside of the side wall, or other components such as on the electromagnetic output 102 and the electromagnetic input 108. The reduction in intensity may also be indicative of a contaminated reflective surface 353.

[0189] Figure 19(b) illustrates a further embodiment having a reflector 355 with a reflective surface 357 inside of the enclosure 120. This allows a contamination test directed towards determining contamination inside of the enclosure 120, such as on the electromagnetic output 102 and input 108. Alternatively, it may be used to determine the condition of the electromagnetic output 102 and input 108. For example, over time and use there may be a deterioration with intensity of output 102, or sensitivity of the input 108 to electromagnetic radiation. 39 2016200789 12 Oct 2016 [0190] In a further form, the result of the contamination test from the outside of the enclosure 120 as shown in Fig. 19(a) is compared with the result from the contamination test of the inside of the enclosure 120 as shown in Fig. 19(b). The comparison can provide an indication of the contamination of the side wall 122 of the enclosure 120 compensating, or ruling out, the contamination or reduction in performance of the electromagnetic output 102 and input 108.

[0191] In another example, the range finding system 100 monitors the signal to noise ratio of the electromagnetic input 108. A decreasing signal to noise ratio may be indicative of dust contamination of one or more components of the range finding system 100. This may be used as an alternative, or in conjunction with the above described contamination test.

[0192] In one form, a program in the program memory 211 causes the processor 209 to direct the controller module 201 to perform a contamination test described above. This may be performed at regular time intervals during operation, on start-up, on shut-down, or if the received radiation at the electromagnetic input 108 has been determined to be lower than expected for the given range of the object7 and/or material of the object7. Furthermore the program, in response to a determination that the range finding system 100 is contaminated, may prompt an operator to service the range finding system 100 and/or shutdown the range finding system 100. This may be important in circumstances where the contaminate is a fire risk.

[0193] In one form, the controller 201 determines the time difference between the electromagnetic output 102 sending a pulse of electromagnetic radiation and the electromagnetic input 108 receiving the reflected pulse of electromagnetic radiation without determining the intensity of the received electromagnetic radiation. In other words, the electromagnetic input 108 acts as a trigger to stop the counting of clock pulses. This avoids the requirement for an ultra-fast analog-digital (A/D) conversion and therefore, reduces the cost, complexity and power consumption of the controller.

[0194] In order to determine contamination of the range finder or the presence of particles in the environment or on the side wall 122, the controller 201 may switch the electromagnetic output 102 from pulse mode to continuous mode and switches the controller port connected to the electromagnetic input 108 from trigger mode to A/D mode. Since the electromagnetic 40 2016200789 12 Oct 2016 output 102 is continuous, a slow A/D conversion as provided by common microcontrollers can be used.

[0195] The result, that is the digital value representing the intensity of the received electromagnetic radiation, can then be compared by processor 209 to a threshold stored on data memory 213. If the result is below the threshold, the processor 209 determines that the contamination is above an acceptable level. The processor 209 may then activate an alarm or activate a control light to indicate excess contamination to an operator. This procedure of determining contamination may be performed periodically. Preferably, this procedure is performed every 10 seconds or after ten revolutions around the central axis 136.

[0196] In one form, stored on data memory 213 are values of azimuth and elevation of the electromagnetic output that are indicative of the direction from the electromagnetic output 102 to a reference mirror (such as reflective surface 353, 357). Processor 209 may then send control data to the controller module 201 to cause the electromagnetic output 102 to be switched to continuous output when the azimuth and elevation of the output 102 are equal to the stored values or within a range, such as 1 degree, of the stored values.

[0197] Processor 209 also sends control data to the controller module 201 to cause the controller port connected to the electromagnetic input 108 to be switched to A/D conversion when the azimuth and elevation of the output 102 are equal to the stored values or within a range, such as 1 degree, of the stored values.

[0198] This way, the distance to the reference mirror 353, 357 is not determined but instead, the contamination can be measured at each evolution of the output 102 around axis 134 without starting and stopping the movement of the output 102, which reduces mechanical stress on the components.

Variations to the configuration of the electromagnetic output and input [0199] A variation of the range finding system 4100 will now be described with reference to Fig. 21(a). In this variation the electromagnetic output 4102 includes a reflector, for example, a mirror. The electromagnetic output 4102 redirects a beam of electromagnetic radiation from the emitter 152 to provide the first beam of electromagnetic radiation 104. The 41 2016200789 12 Oct 2016 electromagnetic input 4108 also includes a reflector, which may also be a mirror. The electromagnetic input 4108 redirects reflected electromagnetic radiation 110 towards an electromagnetic radiation sensor 154. In this embodiment the use of one or more reflectors, in conjunction with the geometry of the side walls 122, provide a second beam path 124 of the second beam 126 that avoids dazzling the sensor 154.

[0200] In another variation, the reflectors of the electromagnetic input 4108 and the electromagnetic output 4102 are formed by a common reflector.

[0201] Another variation of the range finding system 5100 will now be described with reference to Fig. 21(b). In this variation, the electromagnetic output 5102 and the electromagnetic input 5108 are rotatably supported and steered by the second support element 5140 and the first support element 5140. In this variation, the electromagnetic output 5102 provides a first beam 104 that is incident on the side wall 122 at or substantially close to the surface normal. A resultant specular reflection 128 provides a second beam 126 on a second beam path 124 that is direct back towards the electromagnetic output 5102. Nonetheless, in this configuration, the electromagnetic input 5108 is located outside the second beam path 124 to avoid or reducing the effects of specular reflection to the electromagnetic input 5108.

Variation to the side wall of the enclosure [0202] Variations of the range finding system 6100, 7100, 8100 having different configurations of the side wall, including an outer side wall and an inner side wall, will now be described with reference to Figs. 22(a) to 22(c).

[0203] Referring to Fig. 22(a) the range finding system 6100 has an enclosure 120 with an inner side wall 6122a that surrounds the electromagnetic output 102 and input 108. An outer side wall 6122b, in turn, surrounds the inner side wall 6122a. In this embodiment, a void 6131 is defined between the outer side wall 6122b and inner side wall 6122a.

[0204] The outer side wall 6122b and the inner side wall 6122a may be made of different materials. An advantage of using different materials is that different respective properties of the materials can be combined. For example, the outer side wall 6122b may be made of a material with high impact resistant material to provide an impact resistant barrier. The inner 42 2016200789 12 Oct 2016 side wall 6122a may be made of a material that withstands high pressures (such as at least 100 kPa, or at least 500kPa, or at least lOOOkPa). In one embodiment the outer side wall 6122b is constructed of glass to provide scratch resistance. The inner side wall 6122a may be constructed of transparent plastic, such as polycarbonate, to provide a pressure resistant barrier. Therefore the combination of the outer side wall 6122b and inner side wall 6122a may be configured to meet one or more user requirements, which may include conformity to industry standards as discussed herein.

[0205] In another variation, the outer side wall 6122b and inner side wall 6122a are made of the same material with the same or different wall thicknesses. In one embodiment, the outer 6122b and inner 6122a side walls are constructed of glass. Having two side walls may be advantageous in that the outer side wall 6122b can be a sacrificial barrier that can be replaced as required without exposing the electromagnetic output 102 and input 108 to contaminants. This may be particularly advantageous if replacement is done in the field, such as dusty environments often encountered in mines.

[0206] The void 6131 between the outer side wall 6122b and inner side wall 6122a may advantageously provide a standoff to reduce the effect of an impact on the outer side wall 6122b from affecting the inner side wall 6122a and the components of the system contained therein. For example, the outer side wall 6122b may absorb an impact that causes it to deform. However, the void 6131 provides a spacing away from the inner side wall 6122a so that the force of the impact is not directly transmitted to the surface of the inner side wall 6122a.

[0207] Another embodiment of the range finding system 7100 is illustrated by Fig. 22(b) which includes an inner side wall 7122a made of a rigid material surrounded by an outer side wall in the form of a protective film 7122b. The protective film 7122b may be a peelable transparent plastic film that can be removed and replaced when the film is scratched, otherwise damaged or contaminated. Advantageously, the protective film 7122b may provide a low cost and easily replaceable sacrificial barrier to allow ease of maintaining transparency of the enclosure 120. The protective film 7122b may include polyester films similar to those used on racing car windshields, such as those by MADICO, Inc., Woburn, Mass, with product designations LCL-600-XSR and LCL-800-XSR as well as 5-7 mil films sold by that company. 2016200789 12 Oct 2016 43 [0208] Yet another embodiment of the range finding system 8100 is illustrated by Fig. 22(c) which includes an inner side wall 8122a that is laminated or adhered to an outer side wall 8122b using an adhesive layer 8123. The adhesive layer may include a liquid resin is a made from a plastic polymer formulated from an acrylic or silicone base compound. This may be the type that includes photo initiators which will tend to cure the applied resin very quickly when it is exposed to UV light. One such adhesive could be UV CURE 7155 from Epoxies Etc., Deco-Coat Product Line, 21 Starline Way, Cranston, R.I. 02921. In one example, the adhesive agent includes polyvinyl butyral (PVB). The adhesive layer preferably reduces the propensity and/or magnitude of the enclosure to provide multiple reflections of the electromagnetic radiation source as well as providing an impact barrier between the inner and outer wall.

[0209] In an exemplary embodiment, the enclosure 120 comprises a dual walled glass cylinder consisting of an inner 8122a and an outer 8122b side walls formed of glass cylinders laminated together using PVB (polyvinyl butyral) 8123 or other suitable laminating/adhesive substance.

[0210] The outer 6122b and inner 6122a side walls may cause multiple respective points of reflection and refraction of light, such as at location 6128a, 7128a, 8128a at the inner side wall 6122a, 7122a, 8122a and location 6128b, 7128b, 8128b at the outer side wall 6122b, 7122b, 8122b. Adjustments for these effects may be made by calibration and/or calculation as those described earlier but with consideration of the multiple reflections and refractions. Furthermore, the reflection and refraction caused by the adhesive layer 8123 should also be considered.

Other features of the range finding system 100 [0211] In one form the electrical and electronic components (including lasers, motors and controller) inside the enclosure 120 of the range finding device 100 do not consume more than 6W of power to reduce the risk of ignition by the range finding system heating up. It is to be appreciated that the maximum levels of power consumption may vary depending on the relevant standards for the country or jurisdiction. 2016200789 12 Oct 2016 44 [0212] The range finding system 100 preferably conforms one or more (more preferably two or more) of International standard IEC 60079-0; IEC 60079-1; US standards: ANSI/UL1203:2006, British standards BS EN 60079-1:2007; and Australian standards AS60079.1:2007. In a preferred embodiment, the range finding system also conforms to group 1 gas standards (e.g. coal mining environments). It is to be appreciated that some variations of the range finding system may conform to other standards as required for the particular application, which may include other gas group standards such as group IIA, IIB, IIC gas standards.

Applications [0213] The mining machine 3 and range finding system 100 may be particularly suitable for use in environments which are susceptible to fire or explosion, particular upon exposure to an ignition source. In one embodiment, the range finding system 100 of the mining machine 3 is used for determining the range of an object within a mine, in particularly a coal mine. The atmospheric environment within coal mines may contain an explosive and/or flammable mixture of coal dust, methane and oxygen.

[0214] 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 mining machine comprising: - a range finding system comprising: - an electromagnetic output to provide a first beam of electromagnetic radiation along a first beam path; - an electromagnetic input to receive reflected electromagnetic radiation of the first beam from an object for determining a range of the range finding system from the object; -an enclosure including a side wall that surrounds a central axis of the enclosure, the side wall transparent to the electromagnetic radiation provided by the electromagnetic output; and - a first support element rotatable within the enclosure around a first rotation axis, wherein the electromagnetic output and electromagnetic input are disposed within the enclosure and supported by the first support element such that rotation of the first support element: steers the first beam provided by the electromagnetic output; and steers the electromagnetic input to receive the reflected electromagnetic radiation of the first beam from the object, and wherein the electromagnetic output is offset from the central axis so that the first beam path from the electromagnetic output to the side wall does not intersect the central axis and that the electromagnetic input is located outside a second beam path of a second beam of electromagnetic radiation defined by a specular reflection of the first beam on the side wall, - a data port to output relative position data of the mining machine to the object based on at least the determined range.
2. The mining machine according to claim 1 further comprising: - a processing device to: - determine a first position of the mining machine based on the relative position data and an object position of the object.
3. The mining machine according to claim 2 further comprising: - a first sensor system to determine movement data of the mining machine based on dead reckoning; wherein the processing device is further arranged to: - determine a second position of the mining machine based on: - the first position; and - the movement data of the mining machine based on dead reckoning.
4. The mining machine according to either claim 2 or 3 wherein the first position is an absolute position.
5. The mining machine according to claim 1 further comprising: - a first sensor system to determine movement data of the mining machine based on dead reckoning; - a processing device to: - determine a second position of the mining machine based on: - the relative position data; and - the movement data of the mining machine based on dead reckoning.
6. The mining machine according to any one of the preceding claims wherein the first rotation axis is coaxial with the central axis.
7. The mining machine according to any one of the preceding claims further comprising: a second support element to provide support between the electromagnetic output and the first support element, wherein the second support element is rotatable around a second rotation axis, and wherein rotation of the second support element steers the first beam provided by the electromagnetic output.
8. The mining machine according to claim 7 wherein the second rotation axis is perpendicular to the first rotation axis.
9. The mining machine according to any one of the preceding claims further comprising a controller module to steer the first beam to a plurality of orientations to provide a plurality of range determinations of the object(s) in a surrounding environment.
10. The mining machine according to claim 9 wherein the plurality of range determinations of the object(s) in the surrounding environment are represented as data in a three-dimensional point cloud.
11. The mining machine according to any one of the preceding claims wherein the electromagnetic output includes a laser emitter to provide the first beam in the form of laser light and wherein the electromagnetic input includes a light sensor to receive reflected laser light from the object.
12. The mining machine according to any one of the preceding claims wherein the electromagnetic output provides the first beam of electromagnetic radiation that is in one or more of the ultraviolet, visible, and/or infrared spectrums.
13. The mining machine according to any one of the preceding claims wherein the side wall is a cylindrical side wall.
14. The mining machine according to any one of the preceding claims further comprising one or more sealing elements that in conjunction with the side wall seal an inside of the enclosure from outside of the enclosure such that the one or more sealing elements prevent ignition of gas outside the enclosure by ignition triggers from the inside of the enclosure.
15. A method of monitoring a position of a mining machine comprising: - receiving, from a data port in a mining machine according to any one of claims 1 to 14, relative position data of the mining machine to an object having an object position; - receiving an output of a first sensor system indicative of movement data of the mining machine based on dead reckoning; - determining a second position of the mining machine based on: - the relative position data of the mining machine; and - the movement data of the mining machine based on dead reckoning.
16. The method according to claim 15 further comprising the step of; - determining a first position of the mining machine based on the relative position data of the mining machine to the object and the object position.
17. The method according to claim 16 wherein the step of determining a second position of the mining machine is further based on the first position of the mining machine.
18. The method according to either claims 16 or 17 further comprising: - receiving, from a data store, an object position data associated with the object in the data store; wherein the step of determining the first position is further based on the received object position data associated with the object.
19. The method according to any one of claims 15 to 18 wherein the step of determining a second position of the mining machine is further based on a starting position data of the mining machine.
20. A method of determining structural changes in a tunnel in a mining operation comprising: - receiving a first profile scan of the tunnel, wherein the first profile scan is based on receiving a plurality of relative position data from a data port in a mining machine according to any one of claims 1 to 14; - storing the first profile scan in a data store; - subsequently receiving a second profile scan of the tunnel, wherein the second profile scan is based on receiving a plurality of relative position data from the same mining machine or different sensor system; and - processing the first profile scan and the second profile scan to determine any structural change of the surfaces of the tunnel corresponding to deformation in profile of the tunnel.