Method and system for autonomously operating a mining and / or construction machine

Abstract

The present disclosure relates to a method performed by a control system for navigating a mining and / or construction machine (100) from a first position (212) to a second position (222; 421). the method comprises: providing and receiving a representation of the surroundings of the machine (100); providing and receiving a set of waypoints, the waypoints comprising positions defined by coordinates in the representation of the surroundings of the machine (100), the set of waypoints comprising the second position (222; 421); determining a current position of the mining and / or construction machine (100) in the representation of the surroundings of the machine (100), determining control signals for effectuating manoeuvring of the machine (100) from the first position (212) to the second position (222; 421) by traversing waypoints of the received set of waypoints, and manoeuvring the machine (100) to the second position (222; 421).

Description

[0001] METHOD AND SYSTEM FOR AUTONOMOUSLY OPERATING A MINING AND / OR

[0002] CONSTRUCTION MACHINE

[0003] Technical Field

[0004] The present disclosure relates in particular to mining and tunnelling, and more specifically to a method and system for autonomous operation of a mining and / or construction machine. The disclosure also relates to a mining and / or construction machine, as well as a control system that implements the method according to the disclosure.

[0005] Background

[0006] With regard to mining and tunnelling, for example, there is a constant ongoing process of improving, e.g., efficiency, productivity and safety. Examples of changes / improvements that are carried out to an increasing extent is the automation of, fully or partly, and / or to control remotely, various processes occurring in mining.

[0007] It is, for example, often desirable that at least part of the machines that are used in mining / tunnelling can be driven in a fully autonomous mode, i.e. , without an operator being required to influence the steering. Autonomous operation, however, is not always suitable or economically justifiable.

[0008] This may be the case, for example, in environments that constantly change. There exist, for example, mines where new galleries / drifts frequently arise, and where older drifts may be refilled, which normally has an impact on autonomous operation of machines. This may be because a setup of a fully autonomous solution oftentimes is relatively time and resource consuming, and a new setup is at least partially required as soon as the environment in which the autonomous machine is driven changes.

[0009] Consequently, there exist situations where an operator needs to be present at the mining and / or construction machine, e.g., in order to manually manoeuvre the machine. Operator presence at a machine may also be required in certain situations in case the vehicle is being autonomously operated, e.g., in case of a fault. There may also exist other situations when an operator may need to be present at a machine. For reasons of safety, there is in general a desire that machines are not driven by an onboard operator, or an operator at all being present at the machine.

[0010] Summary

[0011] It is an object of the disclosure to provide a method for autonomously navigating a mining and / or construction machine from a first position to a second position that allow navigation also when prerecorded routes are absent.

[0012] According to the present disclosure, it is provided a method performed by a control system for navigating a mining and / or construction machine from a first position to a second position, the method comprising: providing and receiving a representation of the surroundings of the machine; providing and receiving a set of waypoints, the waypoints comprising positions defined by coordinates in the representation of the surroundings of the machine, the set of waypoints comprising the second position; determining a current position of the mining and / or construction machine in the representation of the surroundings of the machine; determining control signals for effectuating manoeuvring of the machine from the first position to the second position by traversing waypoints of the received set of waypoints; and manoeuvring the machine to the second position.

[0013] As was mentioned above, there exist a general desire that machines being used in mining and / or tunnelling are capable of being driven fully autonomously as much as possible. A common type of existing solution to achieve autonomous operation is based on a principle where the machine is first driven manually along a route in a path recording step, i.e. , along the tunnels and / or drifts, along which the machine will later be driven autonomously. At the same time signals from various transmitters arranged on the machine are recorded, so that these manoeuvrings can be “played back” during subsequent autonomous driving to allow the machine to autonomously navigate the recorded path. However, it may not always be possible to operate the machine in this manner, due to the requirement that the machine has been driven beforehand along the route along which the machine is intended to subsequently operate in an autonomous manner. For example, the geographical extension of the tunnel / mine may be constantly changing, e.g., due to ongoing excavation and, therefore, there may oftentimes exist parts of the tunnel / mine which has not been properly set up for autonomous operation of the machine, or where conditions may have changed so that a prerecorded path is no longer usable.

[0014] This may have as consequence that the machine therefore must be driven manually instead. This manual driving may still be effectuated using, e.g., tele-remote control. According to the disclosure, it is provided an alternative method for effectuating, e.g., autonomous and navigation also in parts of the tunnel mine where no pre-recorded routes exist.

[0015] According to the disclosure, it is provided a method that allows navigation such as autonomous navigation in situations where no pre-recorded routes exist. According to the disclosure a representation of the surroundings of the machine, which can be a map representation, is provided and received, where the representation of the surroundings may be provided by a remote system such as a remote-control centre, e.g., by an operator or a remote system that is configured to provide this. For example, the operator may make available a representation of the surroundings in a global coordinate system of the environment, and for a relevant portion of the environment, e.g. covering the environment from the present position of the machine to the desired destination. The provided representation may then be received by the machine, e.g. over any suitable wireless interface.

[0016] In addition to providing and receiving a representation of the surroundings, a set of waypoints are also received, where the set of waypoints, similarly, may be provided, e.g. by the remote system such as the remote-control centre, and be received by the machine. For example, an operator may add the waypoints to the representation of the surroundings, so that representation and set of waypoints can be simultaneously received. The waypoints comprise positions defined by coordinates in the representation of the surroundings of the machine, where one of the waypoints is the second position. The waypoints are hence global coordinates in a coordinate system of the environment in which the machine is operating.

[0017] Furthermore, a current position of the mining and / or construction machine is determined in the representation of the surroundings of the machine. For example, an operator may indicate the machine position in the representation of the surroundings of the machine. The machine may also comprise means such as suitable sensors for determining the machine position in global coordinates to be used in the navigation.

[0018] Control signals for effectuating manoeuvring of the machine from the first position to the second position by traversing waypoints of the received set of waypoints are also determined, and the machine is manoeuvred to the second position.

[0019] In this way, by providing the machine with a representation of the surroundings in global coordinates, hence being a global map, and similarly providing waypoints in the form of global coordinates, as well as determining the machine position, it is possible to provide autonomous navigation also in a situation where no prerecorded route exist, where the surroundings, e.g. may be underground surroundings. It is hence provided a method where navigation is performed using a set of waypoints that are positions being different from a pre-recorded route comprising prerecorded sensor signals.

[0020] According to aspects of the disclosure, there may exist one or more representations of the surroundings, and an identity of the representation of the surroundings to be used may be provided to the machine instead of the actual representation. This may be used in case the machine already have representations stored, e.g., in a control system of the machine.

[0021] According to aspects of the disclosure, the waypoints may be defined, in addition to positions defined by coordinates in the representation of the surroundings, by a pose, that is a direction, of the machine to be manoeuvred towards when reaching the waypoint. The pose may be defined by an angular direction of the machine in the representation of the surroundings. In this way, the machine may perform the navigation in a manner where the direction of the machine is taken into account and a desired direction may be actively manoeuvred towards, e.g. to facilitate continued navigation.

[0022] According to aspects of the disclosure, additional waypoints to be traversed by the machine between two waypoints of the set of waypoints may be calculated and used in the navigation. For example, the additional waypoints may be used to cause a change of direction of the machine towards a requested pose when approaching a waypoint in case a direction is specified for the waypoint.

[0023] According to aspects of the disclosure, the waypoints, in addition to the positions defined by coordinates in the representation of the surroundings of the machine, comprise a requested machine speed to be maintained by the machine when traversing the waypoint. In this way, e.g., an operator or a system may define machine speeds to be used, which may take into account, e.g., curvature and other factors.

[0024] According to aspects of the disclosure, sensor means may be utilized to determine distances to obstacles in the surroundings of the machine, and the machine may be positioned in the representation of the surroundings of the machine by comparing measured distances using the sensor means with corresponding distances in the representation of the surroundings. This provides an efficient way of positioning the machine in the representation of the surroundings as the machine moves from waypoint to waypoint. As an alternative or complement, other means may be used to position the machine. For example, in case the mine is provided with Wi-Fi access points or RFID access points in way that allows, e.g., triangulation this may also be used to position the machine. A brute-force search algorithm may also be used. It is also to be noted that, e.g., dead reckoning may be used in combination with any of the above alternatives. It is also contemplated that, e.g., stereo cameras are used, and radar may also be used. The surrounding topography may also be used to facilitate navigation. According to aspects of the disclosure, the method further comprises, when manoeuvring the machine to a subsequent waypoint in the set of waypoints, to request a steering action of the machine, the requested steering action turning the machine in a direction directly towards the subsequent waypoint. However, prior to manoeuvring the machine according to the requested steering action it is determined whether the requested steering action would cause a collision with a surrounding obstacle within a first time and / or distance of travelling. If this is the case the requested steering action is adjusted such that a steering action causing collision within a first time and / or distance of travelling towards the subsequent waypoint is prevented. In this way the machine may be configured to always attempt to steer towards the subsequent waypoint in the set of waypoints, but where a control function prevents such steering for as long as this is not possible, and forces the machine to follow a route that will not cause collision within a first distance or period of time. This calculation may be continuously performed so that the requested steering action is continuously adjusted to prevent collision.

[0025] According to embodiments of the disclosure a direction from the machine to a subsequent waypoint is calculated, and a steering angle of the machine is requested according to the calculated direction. The steering angle may, e.g., be an angle of steering wheels and / or a joint of, e.g., an articulated machine. The requested steering angle is then adjusted to a steering angle that prevents collision within the first time and / or distance of travelling towards the subsequent waypoint. Hence, even though the navigation may request a steering angle that would turn the machine directly towards the subsequent waypoint, this will be prevented.

[0026] According to aspects of the disclosure, the method may further comprise, when adjusting the requested steering action such as steering angle of the machine to determine a plurality of possible steering actions, such as steering angles, of the machine. A steering action that prevents collision within the first time and / or distance of travelling towards the subsequent waypoint is then selected among the plurality of possible alternatives. In this way various alternatives can be evaluated, and a steering alternative fulfilling set requirements can be selected. The predetermined distance / time may further be arranged to depend on the speed of the machine, where shorter distances may be allowed for lower speeds.

[0027] It may further be repeatedly determined whether the requested steering angle will cause a collision with a surrounding obstacle within a first time and / or distance of travelling, and the requested steering angle may be repeatedly redetermined such that a steering angle causing collision within a first time and / or distance of travelling towards the subsequent waypoint is prevented, and where hence the actual steering action may change in accordance therewith.

[0028] Furthermore, the machine may be configured to, when receiving the sets of waypoints, determining a first waypoint in the set the waypoints, and commence navigation towards the second position by commencing navigation towards the determined first waypoint in the received set of waypoints. The machine may be configured to navigate the waypoints in the order that the waypoints are received in the set of waypoints, or an order that is otherwise indicated in the set of waypoints. When a first waypoint of the set of waypoints is reached, navigation may be continued towards the next indicated waypoint of the set of waypoints, and navigation may be continued until reaching the second position by traversing the waypoints in the order in which they are indicated to be traversed, such as in the order the waypoints are arranged, in the set of waypoints.

[0029] According to embodiments of the disclosure, the method may further comprise to, following commencement of the navigation towards the second position, repeatedly determine the distance to the second position. This may be performed by measuring the distance, e.g. in the representation of the surroundings. The navigation of the machine may be stopped if the distance towards the second position increases during a predetermined period of time and / or a predetermined distance of travel following the commencement of the navigation. In this way it can be determined whether navigation appears to be going in the wrong direction, and a change of direction of travel may be carried out when this is case. As was mentioned, in addition to receiving the position of the waypoints in the representation of the surroundings, a requested machine speed may be received for at least one waypoint of the list of waypoints. The machine speed may also be configured to indicate a direction of motion of the machine for continued navigation when reaching the waypoint. In this way it is possible to change the direction of travel of the machine when reaching a waypoint.

[0030] According to a further aspect, the disclosure relates to a control system for navigating a machine from a first position to a second position. It will be appreciated that all the embodiments described for the method aspects of the disclosure are applicable also to control system aspects of the disclosure. Thus, all the aspects described for methods according to the disclosure may be performed by the control system, which may also be a control device, i.e. , a device. The control system and its embodiments have advantages corresponding to the advantages discussed above with regard to the various aspects of methods according to the disclosure.

[0031] In particular the disclosure relates to a control system for navigating a mining and / or construction machine from a first position to a second position, the control system comprising: means, such as a transmitter device for providing a representation of the surroundings of the machine, and means, such as a receiver device for receiving the representation of the surroundings of the machine; means for providing and means for receiving a set of waypoints, the means, e.g., being the transmitter device and receiver device, the waypoints being positions defined by coordinates in a representation of the surroundings of the machine, the set of waypoints comprising the second position; means, such as a control unit, for determining a current position of the mining and / or construction machine in the representation of the surroundings of the machine, means, such as a control unit, for determining control signals for effectuating manoeuvring of the machine from the first position to the second position by traversing waypoints of the received set of waypoints, and means, such as an actuating system, for manoeuvring the machine to the second position.

[0032] Further characteristics of the present disclosure and advantages thereof are indicated in the detailed description of exemplary embodiments set out below and the attached drawings.

[0033] Brief description of the drawings

[0034] Figs. 1A-B illustrates an exemplary machine which may be configured to operate according to aspects of the disclosure;

[0035] Fig. 2 illustrates an exemplary portion of an environment in which the machine of Figs. 1A-B may be operating;

[0036] Fig. 3 illustrates an exemplary method according to the disclosure;

[0037] Fig. 4 illustrates an exemplary situation using autonomous navigation according to embodiments of the disclosure.

[0038] Detailed description of aspects of the disclosure

[0039] Aspects of the disclosure will be exemplified in the following in view of a particular kind of mining and / or construction machine. The disclosure is, however, applicable for all kinds of mining and / or construction machines that may be set in motion and autonomously move around in an environment. For example, according to aspects of the disclosure, the mining and / or construction machine may comprise a truck, a drilling rig, a rock reinforcement rig, or any other mining and / construction machine that may be set in motion to allow the machine to be driven in an environment such a mine and / or tunnel.

[0040] Figs. 1 A and 1 B illustrates a side view and elevated view, respectively, of an exemplary machine 100, which may be configured to operate according to the present disclosure. According to the present example, the machine 100 is a load- haul-dump (LHD) machine, and is used to load and transport away materials such as excavated rock through the use of a bucket 101 . The machine 100 comprises, apart from the bucket 101 , wheels 102-105 for allowing the machine to be set in motion and a control system comprising at least one control unit 106. The control unit 106 is configured to control various of the functions of the machine 100. Machines of the disclosed kind may comprise a control system equipped with more than one control unit, e.g., a plurality of control units, where each control unit, respectively, may be arranged to be responsible for monitoring and carrying out different functions of the machine 100. For reasons of simplicity, however, it will be assumed in the following that various functions according to the disclosure are controlled by the control unit 106. The control unit 106 may, for example, be configured to control manoeuvring of the machine, e.g., in terms of setting the machine in motion, stopping the machine, and controlling and manoeuvring equipment forming part of or being attached to the machine, such as the bucket 101 , e.g., when loading or unloading rock. Requests for setting the machine in motion may be initiated by a part of the control system controlling autonomous driving of the machine.

[0041] The machine 100 further constitutes an articulated machine, where a front portion 100a is connected to a rear portion 100b by means of a hinge 107, and the machine is steered by means of articulated steering to facilitate manoeuvring of the machine. Machines of the disclosed kind are often driven in surroundings where the distance to surrounding rock walls may be small, and articulated machines may provide manoeuvrability advantages over non-articulated machines in such environments. As is appreciated by a person skilled in the art, the illustrated machine merely forms an example of usability of the disclosure, and, in principle, the disclosure is applicable for essentially any kind of movable machine being utilized in mining and / or construction.

[0042] Motion of the machine 100 and / or equipment thereof, may be generated by setting one or more actuators in motion. Such actuators may comprise cylinders / motors / pumps etc. For example, the machine 100 may comprise actuators in the form of, e.g., hydraulic motors for propelling the machine 100. According to the disclosed example there may also be an actuator in the form of one or more hydraulic cylinders for controlling articulation of the joint 107, and hence steering actions of the machine 100. The machine 100 may also comprise actuators, e.g., in the form of hydraulic cylinders for controlling raising / lowering the bucket 101 , where further actuators may be present in this regard, e.g., to control tipping of the bucket 101.

[0043] Machines of the disclosed kind may e.g., be configured to be controlled by an operator being present in the machine, or configured to be remote-controlled, and / or be autonomously controlled, as is at least partly the case according to the present example.

[0044] The machine may also comprise various further features. For example, the machine may be provided with range detectors such as laser range scanners, such as LIDAR scanners 111 , 112 to determine distances e.g. to surrounding rock and / or obstacles in the travel path of the machine. The machine may also comprise, e.g., front and a rear video cameras, which are connected to the control unit 106 and which may be utilized to transfer video signals to the control unit 106 for further transmission, e.g., to a remote-control operator in a control room in case the machine needs to be remote-controlled, and the cameras may also be used for monitoring and surveillance of an autonomously operating machine, and possibly also be utilized by an operator manually operating the machine.

[0045] As was mentioned above, machines of the kind disclosed in figs. 1 A-B may be of very large dimensions and exhibit substantial mass, and even more so when carrying load, where machines of the disclosed kind may be designed to carry e.g., 10-30 tonnes of broken rock. It is highly desirable that machines of this kind can be driven autonomously as much as possible. According to the present disclosure, it is provided means for increasing the number of situations in which autonomous navigation can be utilised.

[0046] As was also mentioned above, a common method to achieve autonomous operation is to manually drive the machine in a path recording step along a route that the machine subsequently is to drive along in an autonomous manner. The machine may be manually driven, e.g., by an operator being present in the machine or by use of remote-control, during path recording, and the recording may be carried out from a position at which autonomous driving is to be commenced and be stopped at a target position. Simultaneously, machine control signals and sensor signals such as current steering actions and machine speed are recorded. In particular, manoeuvrings of the machine under the influence of the driver are recorded so that these manoeuvrings can be “played back” during subsequent autonomous driving.

[0047] In addition to recording the manoeuvrings that the machine undergo, the direction and distance to obstacles in the surroundings, in general comprising at least rock walls, are determined. Distances and directions in relation to the machine may be measured continuously, e.g., using laser range scanners 111 , 112. Measurements are stored for various machine positions along the path.

[0048] Following the recording of the path, local map representations of the surroundings of the machine while travelling the path can then be created with the aid of the transmitter information for the tunnels / drifts along which the machine is moving, where the map representation may form a local co-ordinate system and the path driven by the machine during the recording is described in this system of coordinates.

[0049] During autonomous navigation the recorded path is played back by the machine, wherein co-ordinate information as to how the vehicle was moved manually and the representation of the surroundings is used to move the vehicle autonomously along the same path that the vehicle travelled during the recording.

[0050] Fig. 2 illustrates an exemplary environment in which the machine according to Figs. 1 A-B may be configured to operate, and where various pre-recorded routes of the exemplified kind may be utilized. Fig. 2 illustrates a schematic top view of an exemplary underground environment. The illustration is highly exaggerated, since normally drifts and tunnels of a mine would likely look very different in reality, and in particular have drifts / tunnels going in various different directions, oftentimes comprising curves etc. The figure is hence for illustration purposes only. The figure schematically illustrates tunnels and drifts surrounded by rock walls, indicated by dashed blocks.

[0051] As was mentioned above, there may exist various prerecorded routes along which machines may travel autonomously. This is illustrated in the figure by dashed lines where circles 210, 211 , 212 represents start- and / or endpoints (in dependence of the direction of travelling) of such prerecorded routes. For example, according to the illustrated example, there is a prerecorded route 201 between start-Zendpoint 210 and start-Zendpoint 211. Similarly, a further prerecorded route 202 exist between start-Zendpoint 211 and start-Zendpoint 212. The machine 100 is currently traveling along prerecorded path 202 towards start-Zendpoint 212. Measurements of the laser range scanner 111 are schematically indicated by dotted lines 230.

[0052] Furthermore, when the machine 100 reaches the end of a prerecorded route, such as when reaching start-Zendpoint 211 coming from start-Zendpoint 210, the machine 100 may be configured to transition from following prerecorded route 201 to continue autonomous navigation by following route 202 instead. When the end of a prerecorded route is reached, the map of a subsequent prerecorded route, if such exists, may, for example, be loaded from a local storage in the control system of the machine or, e.g. be downloaded to the machine, so that the machine thereby may continue traveling towards the planned destination.

[0053] However, as was also mentioned above, the layout of, e.g., a mine is oftentimes constantly changing due to ongoing excavation. There may therefore exist parts of the environment for which no prerecorded routes are available. It is also to be noted that the setup of autonomous operation along prerecorded routes is a timeconsuming task that will need to be repeated as soon as any changes are made along the route for which the recording has been made since the local map representation would no longer correspond to the actual situation. Autonomous operation of this kind may therefore not be feasible in areas that are subject to constant change with the need for manual interaction instead, e.g., through teleremote operation.

[0054] For example, when the machine 100 reaches endpoint 212 and is not scheduled to continue along prerecorded route 203 but where, instead, the machine 100 is to manoeuvre to destination 222, the machine would stop at endpoint 212 expecting an operator to take over the manoeuvring of the machine, e.g., through tele-remote control. According to the disclosure, it is provided an alternative method for effectuating, e.g., autonomous navigation also in parts of the tunnel mine where no prerecorded routes exist, such as from endpoint 212 in Fig. 2 to destination 222. An exemplary method 300 according to the disclosure is illustrated in Fig. 3. The method starts in step 301 by a step of providing and receiving a representation of the surroundings of the machine. In this step, a global representation of the surroundings covering the current machine position, i.e. , endpoint 212 and destination 222 and the area therebetween, is provided, where this representation of the surroundings may be provided by an operator, e.g. located in a remote-control centre, such as remotecontrol centre 260 in the figure, to be received by the machine 100. The representation of the surroundings is a representation generated in the global coordinate system of the environment. Hence, rock walls etc., such as indicated by dashed blocks, are represented by global coordinates, and not local coordinates as is to case with prerecorded map representations. Such global map representations are continuously generated as excavation progress and hence, in step 301 , a relevant portion of such a global map representation is provided, e.g. by the remote-control centre, e.g., by being transmitted, to be subsequently received by the machine 100.

[0055] In step 302 a set of waypoints is provided and received by the machine. Step 302 may be carried out simultaneously with step 301 or even before step 301. In principle an operator may provide a set of waypoints in the representation of the surroundings where the waypoints comprise positions that are determined by coordinates in the representation of the surroundings of the machine, and hence being global coordinates in the coordinate system of the environment. These waypoints may be provided, e.g., by an operator adding such waypoints to representation of the surroundings. For example, the operator may provide the machine 100 with a representation of the surroundings covering the dash / dotted area 240 in Fig. 2 and waypoints 221 and 222, where waypoint 222 represents the position to which the machine is to autonomously travel, i.e. the end position.

[0056] In step 303 a current position of the machine 100 in the representation of the surroundings is determined, and hence the position in the global coordinate system. For example, the operator may provide the current machine position as coordinates in the provided representation of the surroundings. In step 304 control signals for effectuating manoeuvring of the machine from the current position, i.e. position 212 in Fig. 2 to the destination 222 by traversing the waypoints along the way (waypoint 221 according to the example) are determined. The machine 100 is manoeuvred to the destination 222, step 305. Steps 304, 305 may be carried out simultaneously, since control signals may continuously be generated along the route. One the machine 100 reaches the destination 222, e.g., further navigation according to pre-recorded routes may be configured to take place, indicated by dashed line 204.

[0057] According to the present disclosure, it is hence provided a solution where the machine is provided with a representation of the surroundings in a global coordinate system of the surroundings, and waypoints to be traversed in the received representation of the surroundings. The machine may then autonomously navigate to the set destination using suitable means onboard the machine by generating control signals that effectuate a manoeuvring towards the destination where the machine, e.g. using onboard sensor means may compare the current position with the received representation of the surroundings , where the navigation may calculate the distance and direction to the subsequent waypoint, and perform a control that causes the machine to navigate to the next waypoint to achieve a desired navigation to the destination. As will be explained below, further features may be utilised to ensure that collision does not occur.

[0058] This hence provides a method for autonomous navigation that may be used in situations when no pre-recorded routes exist, and thereby alleviate an operator from, e.g., controlling the machine through tele-remote control.

[0059] According to aspects of the disclosure, the waypoints may be defined solely by coordinates in the representation of the surroundings. However, according to embodiments of the disclosure, the waypoints may in addition comprise a pose. That is, a machine direction, that the machine 100 is to be manoeuvred towards when reaching either an intermediate waypoint or the destination. The pose may be represented by a direction, such as an angular direction, in the global coordinate system of the surroundings. It is to be understood that even though only two waypoints 221 , 222 are exemplified in the example of Fig. 2, any suitable number of waypoints may be utilized. Also, the route that the machine 100 is to follow may comprise curves, crossings etc., and the continued navigation may be facilitated if the machine 100 reaches a particular waypoint with the desired pose, since this may make it easier, e.g., to take an upcoming turn or similar action.

[0060] It is also to be noted that, perhaps in particular when using poses, there may exist a need to, in addition to coordinates for the waypoints, generate intermediate waypoints to facilitate the manoeuvring of the machine towards the desired pose. Such additional waypoints may be calculated, e.g., by a path planner and / or path follower that may form part of either the control system of the machine or a separate entity, e.g., located at a remote location in which case additional intermediate waypoints may be downloaded to the machine.

[0061] Furthermore, the waypoints may also, in addition to positions, comprise a requested machine speed to be maintained by the machine when traversing a particular waypoint. For example, if the waypoint is located along a relatively straight portion of a tunnel forming part of the path, the machine speed may be set to a higher machine speed whereas, in case the waypoint is located in a corner, sharp turn or a crossing, for example, the machine speed may be set to a comparatively lower speed. In this way it may be insured that the machine, when autonomously traveling the path, will do this at speeds that are not excessively low or high, and where the speeds may be controlled by an operator when setting the waypoints.

[0062] According to embodiments of the disclosure, the machine speed that has been set for a waypoint may also indicate a direction of motion of the machine for the continued navigation when the particular waypoint is reached. Although not being the case in the example exemplified in Fig. 2, it may be the case that the machine 100, somewhere along the route, may need to change direction of traveling. For example, the machine 100 may need to make a change of direction of motion to reach the desired destination and hence, e.g., at least partly travel in a backwards direction instead of a forward direction for part of the path. This may then be accounted for by indicating, at least for relevant waypoints along the path, that the machine is to change a direction of travel towards the subsequent waypoint along the path when reaching a particular waypoint. This is hence made possible according to the disclosure.

[0063] Further, a machine according to the disclosure will in general be traveling underground or in some other type of location where satellite navigation is not present or possible to utilize. The machine 100 will therefore use other means to accomplish the desired autonomous navigation. Such means may include sensor means such as the laser range scanners 111 , 112 of the machine 100, where these scanners measure distances in various different directions to obstacles surrounding the machine and hence, e.g. to rock walls. This is indicated in Fig. 2 by dotted lines 230. Such measured distances may then be compared with corresponding distances in the representation of the surroundings so that the machine thereby may determine its current location also along the route where such info in general will not be provided by an operator.

[0064] It is also to be understood that use of, e.g., laser range scanners are merely an example of possible technologies that may be used, and that there exist various other techniques that may be used by the machine to accomplish the desired navigation. For example, dead reckoning may be used to estimate travelled distance and thereby current machine location, where dead reckoning may also be used in combination with other techniques. As a further alternative, in case the mine is provided with Wi-Fi access points, RFID access points or other types of wireless transmission means that may be used for positioning, such transmitters may, at least in case a sufficiently high number of access points are available, be used in various positioning techniques, such as, e.g., triangulation.

[0065] Furthermore, according to embodiments of the disclosure, the autonomous navigation of the machine may be further facilitated. The use of mere waypoints as guidance for the machine according to the above may provide a satisfactory solution for accomplishing the desired navigation. However, the navigation may be further facilitated, which as a consequence, e.g., may have as result that higher machine speeds may be made possible to use in the autonomous navigation. Therefore, according to aspects of the disclosure, a method may be utilized where a steering action is requested where the requested steering action would turn the machine towards the subsequent waypoint. The subsequent waypoint may, as in Fig. 2B, be a waypoint that would require that the machine performs a relatively sharp turn. That is, when the machine 100 is present at endpoint 212 and is to travel towards waypoint 221 , a turn directly towards the waypoint 221 would cause the machine to follow dashed line 220A. In some occasions, such a manoeuvre may work fine, but according to the present example such a sharp turn may result in a collision with the corner 250. Instead, it may be desirable that the machine more follows a path in line with the path indicated by solid line 220.

[0066] A further, more extreme example, is also illustrated in Fig. 4, where the machine 100 currently being present at a waypoint 420, and navigating towards a subsequent waypoint 421. Use of the present method of navigation, i.e., determine a steering action straight towards the subsequent waypoint would hence result in a straight line towards waypoint 421 , i.e., a direction 422 going straight through rock. This, apparently, is neither possible nor desirable. One method of alleviating problems of this kind would, of course, to be to add a waypoint, such as, with reference to Fig. 4, e.g., at the location 423. According to embodiments of the disclosure, however, this is solved using other means as will be explained.

[0067] Hence, when a steering action towards the subsequent waypoint is requested, it is first determined whether the requested steering action would cause a collision with the surrounding obstacle, such as corner 250 in Fig. 2 or the rock in Fig. 4, and where it is also determined whether this condition would occur within a first time of travel and / or a predetermined distance of traveling. This determination can be accomplished, for example, by the laser scanner measuring distances in various different directions and in particular in the direction representing the direction that the machine would steer towards in case the requested steering action would be effectuated.

[0068] When it is determined that the distance to collision in this direction is below the predetermined distance, and / or when the time it would take to reach the obstacle is below a predetermined period of time, the requested steering action is adjusted such that collision within the predetermined distance / time is prevented. This may be accomplished, for example by selecting a steering action that as much as possible corresponds to the requested steering action, but where it is ensured that the minimum time / distance requirement is respected.

[0069] It is to be noted in this regard that a plurality of possible steering actions of the machine may be determined and a steering action that prevents collision within the predetermined time / distance may be selected. For example, with respect to Fig. 4, a plurality of possible machine paths 430 for different steering actions, such as steering angles are disclosed, and where these may be evaluated. The time / distance requirement may result in a steering action causing machine path 431 to be selected, i.e. , the machine will steer towards point 424 instead of towards point 421 .

[0070] As can be seen there may be a number of possible steering actions that would result in a direction between the direction towards points 424 and the direction towards point 421 , but where such steering actions may be discarded because the time / distance criterion is not fulfilled. It is also to be noted that, with reference to the example of Fig. 4, as soon as the machine 100 commences traveling towards point 424, the distance to point 424 from the machine 100 may fall below the predetermined distance, and hence the steering action may be continuously adjusted so that the machine is steered towards a point further and further towards point 423 in the figure, thereby continuously preventing collision with the rock wall.

[0071] At some point the machine will reach a position, e.g. position 423, where it may safely carry out a steering action that turns the machine 100 straight towards the destination 421 . The requested steering action is hence repeatedly adjusted so that collision is prevented. The determination as to whether the machine suffers the risk of colliding may further comprise a safety margin, e.g. in terms of a safety distance to the obstacle so that, e.g., a collision may be determined to be expected if the machine will come within this safety distance from the obstacle within the predetermined distance / time. The predetermined distance / time may further be arranged to depend on the speed of the machine, where shorter distances may be allowed for lower speeds.

[0072] The combination of providing a global representation of the surroundings with the waypoint and this method of adjusting requested steering action provides a very efficient way of accomplishing autonomous navigation of a machine.

[0073] According to aspects of the disclosure, the machine may be configured to repeatedly determine the distance to the destination when navigation towards the destination is commenced. The navigation may then be stopped if the distance towards the destination increases during a predetermined period of time or a predetermined distance of travel following the commencement of the navigation. That is, it can be detected whether the machine appears to be traveling in a wrong direction in relation to the destination and when this is the case the machine may be stopped and an operator may be notified so that it can be evaluated whether the ongoing navigation is in fact correct or whether an error has occurred. Alternatively, navigation may be commenced in the opposite direction.

[0074] The machine may be configured to navigate the received waypoints in the order that the waypoints are received. Hence the set of waypoints may indicate the order in which the setpoints are to be traversed by the machine, and the machine may navigate to the waypoints in a given order. In this way it can be ensured that the machine does not take unintended shortcuts during the navigation by skipping one or more waypoints.

[0075] So far, the invention has been described largely with reference to an LHD machine. The invention may be utilized in any kind of movable mining and / or construction machine, in particular machines comprising wheels and / or tracks for propulsion of the machine. The invention is also applicable for underground machines as well machines operating above ground when satellite navigation is not available.

Claims

Claims1 . A method performed by a control system for navigating a mining and / or construction machine (100) from a first position (212) to a second position (222; 421 ), the method comprising: providing and receiving a representation of the surroundings of the machine (100); providing and receiving a set of waypoints, the waypoints comprising positions defined by coordinates in the representation of the surroundings of the machine (100), the set of waypoints comprising the second position (222; 421 ); determining a current position of the mining and / or construction machine (100) in the representation of the surroundings of the machine (100), determining control signals for effectuating manoeuvring of the machine (100) from the first position (212) to the second position (222; 421 ) by traversing waypoints of the received set of waypoints, and manoeuvring the machine (100) to the second position (222; 421 ).

2. A method according to claim 1 , further comprising: defining the waypoints of the set of waypoints, in addition to positions defined by coordinates in the representation of the surroundings, by a pose (direction) of the machine (100) to be manoeuvred towards when reaching the waypoint.

3. A method according to claim 2, wherein the pose is defined by an angular direction of the machine (100) in the representation of the surroundings.

4. A method according to any one of the claims 1 -3, wherein: the waypoints, in addition to the positions defined by coordinates in the representation of the surroundings of the machine (100), comprise a requested machine speed to be maintained by the machine (100) when traversing the waypoint.

5. A method according to any one of the claims 1 -4, further comprising: utilizing sensor means for determining distances to obstacles in the surroundings of the machine (100), and positioning the machine (100) in the representation of the surroundings of the machine (100) by comparing measured distances using the sensor means with corresponding distances in the representation of the surroundings.

6. A method according to any one of the claims 1 -5, further comprising, when manoeuvring the machine (100) to a subsequent waypoint: requesting a steering action of the machine (100), the requested steering action turning the machine (100) in a direction directly towards the subsequent waypoint; determining whether the requested steering action will cause a collision with a surrounding obstacle within a first time and / or distance of travelling, and adjusting the requested steering action such that a steering action causing collision within a first time and / or distance of travelling towards the subsequent waypoint is prevented.

7. A method according to claim 6, further comprising: calculating a direction from the machine (100) to a subsequent waypoint, requesting a steering angle of the machine (100) according to the calculated direction, adjusting the requested steering angle to a steering angle that prevents collision within the first time and / or distance of travelling towards the subsequent waypoint.

8. A method according to claim 7, further comprising, when adjusting the requested steering angle of the machine (100): determining a plurality of possible steering angles of the machine (100), and selecting a steering angle that prevents collision within the first time and / or distance of travelling towards the subsequent waypoint.

9. A method according to claim 7 or 8, further comprising: repeatedly determining whether the requested steering angle will cause a collision with a surrounding obstacle within a first time and / or distance of travelling, and repeatedly adjusting the requested steering angle such that a steering angle causing collision within a first time and / or distance of travelling towards the subsequent waypoint is prevented.

10. A method according to any one of the claims 1 -9, further comprising: when receiving the sets of waypoints, determining a first waypoint in the set the waypoints, and commencing navigation towards the second position (222; 421 ) by commencing navigation towards the determined first waypoint in the received set of waypoints in a direction towards the second position (222; 421 ).11 . A method according to any one of the claims 1 -10, further comprising: navigating to the second position (222; 421 ) by navigating to the waypoints of the received set of waypoints in a specified order being indicated in the set of waypoints.

12. A method according to any one of the claims 1-11 , further comprising: following commencement of the navigation towards the second position (222; 421 ), repeatedly determining the distance to the second position (222; 421 ), and stopping navigation of the machine (100) if the distance towards the second position (222; 421 ) increases during a predetermined period of time and / or a predetermined distance of travel following the commencement of the navigation.

13. A method according to one of the claims 1 -12, further comprising: in addition to receiving the position of the waypoints in the representation of the surroundings, receiving a requested machine speed for at least one waypoint of the list of waypoints, the machine speed indicating atleast a direction of motion of the machine (100) for continued navigation when reaching the waypoint.

14. A method according to one of the claims 1 -13, wherein: the sensor means for positioning the machine (100) in the representation of the surroundings comprises one or more from: scanning laser sensors, radar sensors, LIDAR sensors, one or more cameras, steering angle sensors, odometer sensors, one or more radio receivers for receiving WI-FI, RFID or other wireless signals, a radar sensor, a brute-force scanning matching sensor.

15. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to any one of the claims 1 -14.

16. Computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of the claims 1 -14.

17. A control system for navigating a mining and / or construction machine (100) from a first position (212) to a second position (222; 421 ), the control system comprising: means for providing and means for receiving a representation of the surroundings of the machine (100); means for providing and means for receiving a set of waypoints, the waypoints being positions defined by coordinates in a representation of the surroundings of the machine (100), the set of waypoints comprising the second position (222; 421 ); means for determining a current position of the mining and / or construction machine (100) in the representation of the surroundings of the machine (100), means for determining control signals for effectuating manoeuvring of the machine (100) from the first position (212) to the second position (222; 421 ) by traversing waypoints of the received set of waypoints, andmeans for manoeuvring the machine (100) to the second position (222; 421 ).

18. A mining and / or construction machine (100) comprising the control system according to claim 17.

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