VEHICLE

FIELD OF THE INVENTION

The present application relates generally to a trolley-assisted mining vehicle . More speci fically, the present application relates to contact force controlling in the trolley-assisted mining vehicle .

BACKGROUND OF THE INVENTION

Trolley-assisted vehicles are used especially in public transport . Trolley-systems have been used to supply power for movable machines and vehicles also in underground mining . Capabilities o f the trolley-systems to operate in a more optimal way may be however further improved .

SUMMARY

This summary is provided to introduce a selection of concepts in a simpli fied form that are further described below in the detailed description . This summary is not intended to identi fy key features or essential features of the claimed subj ect matter, nor is it intended to be used to limit the scope of the claimed subj ect matter . The scope of protection sought for various embodiments of the present disclosure is set out by the independent claims .

Example embodiments of the present disclosure enable keeping a contact force between a trolley-assisted mining vehicle and a trolley line at wanted level regardless of whether the trolley-assisted mining vehicle travels uphill or downhill . This and other benefits may be achieved by the features of the independent claims . Further advantageous implementation forms are provided in the dependent claims , the description, and the drawings .

According to a first aspect , an actuator arrangement for a trolley-assisted mining vehicle is disclosed . The actuator arrangement may comprise at least one trolley pole , wherein a trolley pole may compri se a proximal end and a distal end, wherein the trolley pole may be arranged from the proximal end to a support arrangement , and the distal end of the trolley pole may comprise a slide configured to feed in electrical energy from a trolley line to and/or from the trolley- assisted mining vehicle ; and at least one actuator, which may be configured to raise and lower the trolley pole and to press the slide against the trolley line to form a contact force between the slide and the trolley line ; wherein the contact force may be configured to be maintained inside a target range by increasing or decreasing pressure or power of the at least one actuator . This means that only one actuator may move the trolley pole up and down . Also the actuator may be used to maintain a constant sliding contact between the slide and the trolley line when the trolley-assisted mining vehicle is connected to the trolley line . The actuator arrangement may further comprise a controller configured to control the contact force of the at least one slide based on pressure or power information received from the at least one actuator . The controller may be coupled further to at least one inclinometer of the mining vehicle so that the contact force may be controlled based on pressure or power information received from the at least one actuator and based on tilt information received from the at least one inclinometer .

According to an example embodiment of the first aspect , the at least one actuator may be an electrically, pneumatically, or hydraulically operated actuating device . This allows various actuators to be used for moving the trolley pole up and down . With the hydraulic or pneumatic actuator, the pressure may be directly proportional to the power .

According to an example embodiment of the first aspect , the pressure or power of the at least one actuator may be directly proportional to the contact force ; and the contact force may be configured to be maintained inside the target range by increasing or decreasing the pressure or power of the at least one actuator . When the pressure or power of the actuator is known the contact force may be controlled by adj usting the pressure or power of the actuator and therefore additional sensors are not needed for measuring the contact force . The pressure or power may be used to determine the required contact force to maintain a constant sliding contact between the slide and the trolley line . The trolley- assisted mining vehicles may comprise shorter trolley poles , for example about 2 -4 m, preferably about 3 m . Longer trolley poles , such as 6-7 m long, may be used in busses . The shorter trolley poles may be sti f fer making contact force estimation much easier .

According to an example embodiment of the first aspect , the target range may comprise a target minimum and a target maximum value for the contact force , wherein i f the contact force is below the target minimum value the pressure or power of the at least one actuator may be configured to be increased; and i f the contact force is above the target maximum value the pressure or power of the at least one actuator may be configured to be increased . When the contact force is inside the target range wear of the trolley lines may be decreased and maintenance interval for the trolley lines may be extended . Since ramps and roads in mines may not be completely smooth, it may not be worth trying to keep the contact force at one constant value but between the minimum and maximum values .

According to an example embodiment of the first aspect , the contact force is further configured to be controlled according to a ramp angle to keep the contact force inside the target range , i f the ramp angle is more than 0 ° the pressure or power of the at least one actuator may be configured to be increased to increase the contact force ; and i f the ramp angle is less than 0 ° the pressure or power of the at least one actuator is configured to be decreased to decrease the contact force . When the trolley-assisted mining vehicle travels up, gravitational pull may decrease the contact force and while going down, the contact force may be increased . Poor road conditions in mining environment may cause much variation in the ride height of the slides . When the pressure or power of the actuator is known the contact force may be controlled accurately according to the ramp angle by controlling the pressure or power of the actuator . The contact force may be kept inside the target range regardless of whether the machine travels uphill or downhill . The contact may be kept even in bad road conditions as the actuator may react automatically to changes i . e . pits and bumps of the road . Due to the asymmetric pits or bumps , the trolley-assisted mining vehicle may oscillate laterally . The adj ustable actuator arrangement may compensate for lateral movements or swinging better than a normal spring li ft because it may react more closely to changes in both directions when the spring li ft may only li ft .

According to an example embodiment of the first aspect , the actuator arrangement may comprise the at least one actuator arranged on a first and/or a second side of the trolley pole . Hence , various amounts of the actuators located in di f ferent places may be used for moving the trolley pole up and down or doing other tasks for example , to help adj ust the contact force , to provide accuracy, or to stabili ze the movement of the trolley pole .

According to an example embodiment of the first aspect , one actuator may be arranged on the first side of the trolley pole ; and one actuator may be arranged on the second side of the trolley pole . Actuators arranged on both sides of the trolley pole may give stability and more strength to the movement when the trolley pole is li fted or lowered .

According to an example embodiment of the first aspect , two actuators may be arranged on the first side of the trolley pole ; and/or two actuators may be arranged on the second side of the trolley pole . Two actuators on one side of the trolley pole may give possibility to use two di f ferent actuators for di f ferent tasks , for example , one actuator may be used to move the slide up and down and the other actuator may be used to adj ust the contact force .

According to an example embodiment of the first aspect , the at least one actuator may comprise a first end and a second end, wherein the at least one actuator may be configured to be movably arranged from the first end to the support arrangement or to a frame structure of the trolley-assisted mining vehicle ; and/or the at least one actuator may be configured to be movably arranged from the second end to the trolley pole . An advantage of this is that the actuator may be moved and/or rotated at its one end or both ends at the same time as the trolley pole is turned . The actuator may have at least one contact point to the trolley pole .

According to an example embodiment of the first aspect , the at least one actuator may comprise a connecting element at the first and/or the second end, and wherein the connecting element may be a j oint , a spring, compliant material , a compliant j oint , or a compliant hinge . Various ways of connections may be used for connecting the actuator to the trolley pole , support arrangement , or frame structure of the trolley-assisted mining vehicle . Also , movable , compliant , and/or a flexible connection may be easily achieved by these . According to an example embodiment of the first aspect , a length axis of the at least one actuator may be substantially parallel to a length axis of the trolley pole , and/or the length axis of the at least one actuator may be substantially perpendicular to a length axis of the trolley pole . Thus , di f ferent actuators may be used in di f ferent positions to give di f ferent ef fect when the trolley pole is li fted or lowered .

According to an example embodiment of the first aspect , the trolley pole may comprise an angular or straight form . The straight trolley pole may have simpler mechanics and may be easier to manufacture . However, the angled trolley pole may be used in situations where the actuator is placed below, on at least one side , and/or on top of the trolley pole , for example .

According to an example embodiment of the first aspect , the actuator arrangement may comprise a controller coupled to the at least one actuator, wherein the controller may be configured to control the contact force of the at least one slide based on pressure or power information received from the at least one actuator . The controller may be used to control rising and lowering of the trolley pole to keep the contact force constant between the current controller and the trolley line regardless of the road conditions .

According to an example embodiment of the first aspect , the controller may be configured to receive the pressure or power information from the at least one actuator ; calculate an actual contact force from the received pressure or power information; compare the actual contact force to the contact force target range ; and i f the actual contact force is outside the target range , to increase or decrease the pressure or power of the at least one actuator to maintain the contact force inside the target range . The controller may calculate the present contact force from the pressure or power information and based on that the controller may increase or decrease the pressure or power of the at least one actuator . This may make the actuator arrangement very simple without the need for complex calculation and/or measuring systems .

According to a second aspect , a method for controlling a contact force with an actuator arrangement for a trolley-assisted mining vehicle is disclosed . The actuator arrangement may comprise at least one trolley pole , wherein a trolley pole may comprise a proximal end and a distal end, wherein the trolley pole may be arranged from the proximal end to a support arrangement ; and the distal end of the trolley pole may comprise a slide , which may be configured to feed in electrical energy from a trolley line to and/or from the trolley- assisted mining vehicle ; and at least one actuator ; wherein the method may comprise raising and lowering the trolley pole by the at least one actuator ; pressing the slide against the trolley line by the at least one actuator to form a contact force between the slide and the trolley line ; and maintaining the contact force inside a target range by increasing or decreasing pressure or power of the at least one actuator . Only one actuator may be needed to move the trolley pole both up and down and to maintain a constant sliding contact between the slide and the trolley line when the trolley-assisted mining vehicle is connected to the trolley line .

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings , which are included to provide a further understanding of the invention and constitute a part of this speci fication, illustrate embodiments of the invention and together with the description help to explain the principles of the invention . In the drawings :

Figure 1 shows a simpli fied side view of a mining vehicle comprising an actuator arrangement in which examples of disclosed embodiments may be applied; Figure 2 shows an example of a simpli fied view of the actuator arrangement from above ;

Figure 3 shows an example of a simpli fied side view of the actuator arrangement ;

Figure 4 shows another example of a simpli fied side view of the actuator arrangement ;

Figure 5 shows a further example of a simplified side view of the actuator arrangement ;

Figure 6 shows an example of forces ef fecting to a trolley pole ;

Figure 7 shows another example of the forces ef fecting to the trolley pole ;

Figure 8 shows a further example of the forces ef fecting to the trolley pole ; and

Figure 9 shows an example method according to an example embodiment of the invention .

Like references are used to designate like parts in the accompanying drawings .

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments , examples of which are illustrated in the accompanying drawings . The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utili zed . The description sets forth the functions of the example and the sequence of steps or operations for constructing and operating the example . However, the same or equivalent functions and sequences may be accomplished by di f ferent examples .

According to an example embodiment , trolley- assisted mining vehicle comprises an actuator arrangement and a working machine . The working machine may be a mining vehicle or an underground mining vehicle , for example , a dump truck, a load haul dump ( LHD) vehicle , a drill rig, a development drill , a drilling machine , a bolting or reinforcing vehicle , a rock removal machine , a longhole drill rig, an explosive charging machine , a loader, a transport vehicle , a loading or hauling machine , setting vehicles of gallery arcs or nets , a shotcrete machine , a crusher, or a measuring vehicle . The trolley-assisted mining vehicle may be powered by a trolley line when the trolley-assisted mining vehicle is coupled to the trolley line and by a power source of the mining vehicle when the mining vehicle is decoupled from the trolley line . Correspondingly, the trolley- assisted mining vehicle may be configured for coupling to and decoupling from the trolley line during operation of the trolley-assisted mining vehicle . The coupling may refer to attachment of the trolley-assisted mining vehicle to the trolley line for trans ferring power from the trolley line to or from the mining vehicle . Correspondingly, decoupling may refer to detachment of the trolley-assisted mining vehicle from the trolley line . It should be understood that the trolley-assisted mining vehicle may be configured for being powered by the power source even when the mining vehicle is coupled to the trolley line , fully or partially . Additionally or alternatively, the trolley-assisted mining vehicle may be configured for an energy storage , such as a battery, of the power source being charged from the trolley line when the trolley-assisted mining vehicle is coupled to the trolley line .

Figure 1 depicts example of a simpli fied trolley assisted mining vehicle 100 only showing some elements and functional entities , whose implementation may di f fer from what is shown . It is apparent to a person skilled in the art that the trolley-assisted mining vehicle 100 may comprise also other functions and structures than those shown in Figure 1 .

The embodiments are not , however, restricted to the trolley assisted mining vehicle 100 given as an example but a person skilled in the art may apply the solution to other trolley-assisted mining vehicles provided with necessary properties .

The example of Figure 1 shows a simpli fied side view of the trolley assisted mining vehicle 100 comprising an actuator arrangement . Any functionality disclosed herein may also be applied as a method .

According to an example embodiment , the trolley-assisted mining vehicle 100 comprises an actuator arrangement . The mining vehicle 100 may be arranged to receive current from trolley lines 200 , arranged at a set distance from each other and a distance from the vehicle 100 . The actuator arrangement may be arranged to the trolley-assisted mining vehicle 100 . The actuator arrangement may comprise at least one trolley pole 10 . A trolley pole 10 may comprise a proximal end 12 and a distal end 13 . The trolley pole 10 may be arranged from the proximal end 12 to a support arrangement 30 , and the distal end 13 of the trolley pole 10 may comprise a slide 11 configured to feed in electrical energy from a trolley line 200 to and/or from the trolley-assisted mining vehicle 100 . The actuator arrangement may further comprise at least one actuator 1 which may be configured to raise and lower the trolley pole 10 and to press the slide 11 against the trolley line 200 to form a contact force Fi , F2 , Fa between the slide 11 and the trolley line 200 . The contact force Fi , F2 , Fa may be configured to be maintained inside a target range by increasing or decreasing pressure or power of the at least one actuator 1 . The actuator 1 may be arranged for moving the trolley pole 10 between a first position in which the slide 11 may be in contact with the trolley line 200 , and a second position in which the slide may not be in contact with the trolley line 200 . In an example embodiment illustrated in figure 1 the trolley-assisted mining vehicle 100 comprises two trolley poles 10 , which are in the first position connected to the trolley line 200 ( i . e . , upper position) . In the first position the slides 11 of each trolley pole 10 may be in contact with the respective trolley lines 200 . The second position ( i . e . , lowered position) of the trolley poles 10 is illustrated with dashed lines in Figure 1 . The trolley poles 10 may be lowered by the at least one actuator 1 , for example , by turning the trolley poles 10 around an axis that is in a hori zontal cross direction with a main moving direction M of the mining vehicle 100 .

According to an example embodiment the at least one actuator 1 may comprise an electrically, pneumatically, or hydraulically operated actuating device , which may be used for moving trolley poles 10 , for example from an upper position to a lower position .

Figure 2 shows an example of a simpli fied view of an actuator arrangement from above . The trolley-assisted mining vehicle 100 according to figure 1 may comprise the actuator arrangement of figure 1 . According to an example embodiment the actuator arrangement may comprises at least one actuator larranged on a first and/or a second side 6 , 7 of a trolley pole 10 . This means that there may be one or more actuators 1 on both sides 6 , 7 of the actuator 1 or one or more actuators 1 only on one side 6 , 7 of the trolley pole 10 . It may also be possible that at least one actuator 1 may be located above or below the trolley pole 10 . An example of figure 2 shows that there are two trolley poles 10 and for each one actuator 1 is arranged on the first side 6 of the trolley pole 10 and one actuator 1 is arranged on the second side 7 of the trolley pole 10 . Attaching more than one actuator to the trolley pole may give stability and more strength to the movement when the trolley pole 10 is li fted or lowered .

Figures 3 to 5 show examples of a simpli fied side views of an actuator arrangement , wherein actuators 1 , 1A, IB may be located in di f ferent places around a trolley pole 10 . The actuator 1 , 1A, IB may be arranged on a lower portion of the trolley pole 10. According to an example embodiment at least one actuator 1,1A, IB may comprise a first end 2 and a second end 3. The at least one actuator 1,1A, IB may be configured to be movably arranged from the first end 2 to a support arrangement 30 or to a frame structure 40 of a trolley-assisted mining vehicle 100. According to an example embodiment the at least one actuator 1,1A, IB may be configured to be movably arranged from the second end 3 to the trolley pole 10. This way the actuator 1,1A, IB may be moved and/or rotated from its one end or both ends at the same time as the trolley pole 10 is turned. The actuator 1,1A, IB may always have only one contact point to the trolley pole 10. The length of the actuator 1,1A, IB may be about one third of the length of the trolley pole 10, for example.

According to an example embodiment, the at least one actuator 1,1A, IB may comprises a connecting element 4 at the first and/or the second end 2,3. The connecting element 4 is for example, a joint, a spring, compliant material, a compliant joint, or a compliant hinge. The movable, compliant and/or a flexible connecting element 4 may make it easy to attach the actuator 1,1A, IB and also use it.

An example of figure 3 shows only one actuator 1 attached on the first side 6 of the trolley pole 10. There may also be another actuator 1 attached on the second side 7 of the trolley pole 10 at the corresponding or different position. The actuator 1 may be attached from the first end 2 to the support arrangement 30 and from the second end 3 to the trolley pole 10. The actuator 1 may be substantially parallel to the trolley pole 10.

An example of figure 4 shows only one actuator 1 attached on the first side 6 of the trolley pole 10. There may also be another actuator 1 attached on the second side 7 of the trolley pole 10 at the corresponding or different position. The actuator 1 may be attached from the first end 2 to the frame structure 40 and from the second end 3 to the trolley pole 10. This actuator may be substantially perpendicular to the trolley pole 10.

An example of figure 5 shows a first and second actuator 1A, IB attached on the first side 6 of the trolley pole 10. There may also be a first and second actuator 1A, IB attached on the second side 7 of the trolley pole 10 at the corresponding or different positions. The first actuator 1A may be attached from the first end 2 to the support arrangement 30 and from the second end 3 to the trolley pole 10. The first actuator 1A may be substantially parallel to the trolley pole 10. The second actuator IB may be attached from the first end 2 to the frame structure 40 and from the second end 3 to the trolley pole 10. The second actuator IB may be substantially perpendicular to the trolley pole 10. The first actuator 1A may be used to move the trolley pole 10 up and down and the second actuator IB may be used to adjust the contact force Fi,F2,Fa, for example.

According to an example embodiment, a length axis Ei of the at least one actuator 1, 1A is substantially parallel to a length axis T of the trolley pole 10 and/or the length axis Ei of the at least one actuator 1,1B is substantially perpendicular to a length axis T of the trolley pole 10. Actuators 1,1A, IB in different positions may give different effect when lifting or lowering the trolley pole 10.

According to an example embodiment, the trolley pole 10 comprises an angular or straight form. The trolley pole 10 of the examples of figures 3 to 5 have an angular form. The angled trolley pole 10 may be used when the actuator 1,1A is placed below, on at least one side 6,7, or on top of the trolley pole 10, for example. However, when the actuator 1,1B may be attached from the first end 2 to the frame structure 40 and from the second end 3 to the trolley pole 10 the form of the trolley pole 10 may also be straight, which may make manufacturing easier.

According to an example embodiment, the actuator 1,1A, IB may be used to control both raising and lowering of a slide 11. Pressure or power of at least one actuator 1,1A, IB may be directly proportional to a contact force Fi,F2,Fa. By controlling the pressure or power, a contact force Fi,F2,Fa may be controlled accurately according to a ramp angle 8. Thus, the contact force Fi, F2, Fa may be kept at wanted level regardless of whether a trolley-assisted mining vehicle 100 travels uphill or downhill. With appropriate contact force Fi,F2,Fa, wear of a trolley line 200 may be decreased. Also, possibility to adjust the contract force Fi,F2,Fa may give a suitable maintenance interval for the trolley lines 200. A contact between the trolley-assisted mining vehicle 100 and the trolley line 200 may be kept even in bad road conditions as the actuator 1,1A, IB may react automatically to changes. When the trolley-assisted mining vehicle 100 drives into a pit, the actuator 1,1A, IB may raise the trolley pole 10 to keep the correct pressure or power and the contact force Fi,F2,Fa. When the trolley-assisted mining vehicle 100 drives over a bump, the actuator 1,1A, IB may lower the trolley pole 10 to keep the correct pressure or power and the contact force Fi , F2 , F3.

An example of figures 6 to 8 show how different forces effect to a trolley pole 10. An example of Figure 6 shows the trolley pole 10 of a trolley-assisted mining vehicle 100, wherein the mining vehicle 100 drives on a flat terrain. First point A is a trolley pole mass centre. Second point B is a point between a fourth and third point O,C. The second point B may also be a point where the trolley pole 10 may have an angle if the trolley pole has an angular and not a straight form. The third point C is a point at a distal end 13 of the trolley pole 10 , where a slide 11 may be located and where a contact force Fi acts . The fourth point 0 is a j oint at the proximal end 12 of the trolley pole 10 for the trolley pole 10 turning . Length LI is a length between the fourth point 0 and the second point B . Length L2 is a length between the second point B and the third point C . Length LI is between 400-500 mm and length L2 is between 2500-3000 mm, for example . Gravitational pull from the point A may cause a gravitational force G _y , which may generate proximal end torque Moi at the fourth point 0. The proximal end torque Moi may be opposite to that torque , which may be created by the actuator 1 , 1A, IB for the slide 11 and it may decrease the contact force FI , F2 , FS at the end of the trolley pole 10 .

According to an example embodiment , the pressure or power of at least one actuator 1 , 1A, IB is directly proportional to a contact force Fi , F2 , Fa, and the contact force Fi , F2 , Fa is configured to be maintained inside a target range by increasing or decreasing the pressure or power of the at least one actuator 1 , 1A, IB . The pressure or power of the at least one actuator 1 , 1A, IB may be used to determine the required contact force Fi , F2 , Fa to maintain a constant sliding contact between the slide 11 and a trolley line 200 .

An example of Figure 7 shows the trolley pole 10 of the trolley-assisted mining vehicle 100 , wherein the mining vehicle 100 drives uphill . Travelling uphill may increase a gravitational angle y between an arm of a force r and the gravitational pull G _y . This may lead to the greater proximal end torque Moi at the fourth point 0 causing a decreased contact force Fi .

An example of Figure 8 shows the trolley pole 10 of the trolley-assisted mining vehicle 100 , wherein the mining vehicle 100 drives downhill . Travelling downhill may decrease a gravitational angle 5 between the arm of the force r and the gravitational pull G _y . This may lead to the lower proximal end torque Moi at the fourth point 0 causing an increased contact force Fa. According to an example embodiment, change in the contact force Fi, Fa, Fa with 10 deg a ramp angle £ (17 % ramp) may be +20 % in downhill and -20 % in uphill.

The contact force Fi,Fa,Fa may be maintained inside a target range by increasing or decreasing pressure or power of the at least one actuator 1,1A, IB. According to an example embodiment the target range comprises a target minimum and a target maximum value for the contact force FI, FI, F3. If the contact force FI, FI, F3 is below the target minimum value the pressure or power of the at least one actuator 1,1A, IB may be configured to be increased. If the contact force FI, FI, F3 is above the target maximum value the pressure or power of the at least one actuator 1,1A, IB may be configured to be increased. When the contact force FI, FI, F3 is inside the target range wear of the trolley lines 200 may be decreased .

According to an example embodiment the contact force FI, F2, FS is further configured to be controlled according to the ramp angle £ to keep the contact force Fi , Fi , F3 inside the target range. If the ramp angle £ is > 0° the pressure or power of the at least one actuator FI, FI, F3 may be configured to be increased to increase the contact force FI, FI, F3. If the ramp angle £ < 0° the pressure or power of the at least one actuator 1,1A, IB may be configured to be decreased to decrease the contact force FI, FI, F3. Thus, the contact force Fi,Fi,F3 may be kept inside the target range regardless of whether the mining vehicle 100 travels uphill or downhill. The contact may be kept even in bad road conditions as the actuator 1,1A, IB may react automatically to changes i.e. pits and bumps of a road. The actuator arrangement or the mining vehicle 100 may have at least one inclinometer to determine the ramp angle £.

According to an example embodiment, the actuator arrangement comprises a controller 5 coupled to at least one actuator 1 , 1A, IB . The controller 5 may also be coupled to at least one inclinometer . The controller 5 may be configured to control a contact force FI , F2 , FS of at least one slide 11 based on pressure or power information received from the at least one actuator 1 , 1A, IB . According to an example embodiment , the controller 5 may be configured to control the contact force Fi , F2 , Fa of the at least one slide 11 based on pressure or power information received from the at least one actuator 1 , 1A, IB and based on tilt information received from the at least one inclinometer . Thus , the controller 5 may control the contact force Fi , F2 , Fa of all actuators 1 , 1A, IB of all trolley poles 10 at the same time . The controller 5 may take care that the contact force Fi , F2 , Fa is inside the target force . The controller 5 may be the vehicle controller 5 of the mining vehicle 100 . The controller 5 may comprise one or more processors . It may also comprise one or more memories and computer program code for performing any of the applicable operations disclosed herein . The controller 5 may further comprise a communication interface configured to enable the apparatus to send and/or receive information wired or wirelessly .

The controller 5 as described above may be implemented in software , hardware , application logic or a combination of software , hardware and application logic . The application logic, software or instruction set may be maintained on any one of various conventional computer-readable media . A "computer-readable medium" may be any media or means that can contain, store , communicate , propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus , or device , such as a computer . A computer-readable medium may comprise a computer-readable storage medium that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus , or device, such as a computer. The examples can store information relating to various processes described herein. This information can be stored in one or more memories, such as a hard disk, optical disk, magnetooptical disk, RAM, and the like. One or more databases can store the information used to implement the embodiments. The databases can be organized using data structures (e.g., records, tables, arrays, fields, graphs, trees, lists, and the like) included in one or more memories or storage devices listed herein. The databases may be located on one or more devices comprising local and/or remote devices such as servers. The processes described with respect to the embodiments can include appropriate data structures for storing data collected and/or generated by the processes of the devices and subsystems of the embodiments in one or more databases.

The controller 5 may be implemented using one or more general purpose processors, microprocessors, digital signal processors, micro-controllers, and the like, programmed according to the teachings of the embodiments, as will be appreciated by those skilled in the computer and/or software art(s) . Appropriate software can be readily prepared by programmers of ordinary skill based on the teachings of the embodiments, as will be appreciated by those skilled in the software art. In addition, the embodiments can be implemented by the preparation of application-specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be appreciated by those skilled in the electrical art(s) . Thus, the embodiments are not limited to any specific combination of hardware and/or software.

According to an example embodiment, the controller 5 may be configured to receive the pressure or power information from the at least one actuator 1,1A, IB, calculate an actual contact force Fi,F2,Fa from the received pressure or power information, and compare the actual contact force Fi,F2,Fa to the contact force target range. According to an example embodiment, the controller 5 may be configured to receive the pressure or power information from the at least one actuator 1,1A, IB and the tilt information from the at least one inclinometer, calculate an actual contact force Fi,F2,Fa from the received pressure or power information and the tilt information, and compare the actual contact force Fi, F2, Fa to the contact force target range. If the actual contact force Fi,F2,Fa is outside the target range, the controller 5 may be configured to increase or decrease the pressure or power of the at least one actuator 1,1A, IB to maintain the contact force Fi,F2,Fa inside the target range.

The mining vehicle may have a controller 5 for maintaining the contact force within a definable target range. The controller 5 may be connected to the actuator 1,1A, IB for receiving the actual value of the contact force Fi , F2 , Fa , designed to compare the actual value with the target range, and connected to the actuator 1,1A, IB. The actuator 1,1A, IB may be designed to raise or lower the at least one trolley pole 10 depending on the result of the comparison.

Example embodiments of the present disclosure may thus enable that the contact force may always be kept within the target range, which ensures uninterrupted contact with little trolley line wear.

Figure 9 illustrates an example of a method for controlling a contact force Fi,F2,Fa with an actuator arrangement for a trolley-assisted mining vehicle 100. The actuator arrangement may comprise at least one trolley pole 10. The trolley pole 10 may comprise a proximal end 12 and a distal end 13. The trolley pole 10 may be arranged from the proximal end 12 to a support arrangement 30. The distal end 13 of the trolley pole 10 may comprise a slide 11 configured to feed in electrical energy from a trolley line 200 to and/or from the trolley-assisted mining vehicle 100. The actuator arrangement may further comprise at least one actuator.

At operation 900, the method may comprise raising and lowering the trolley pole 10 by the at least one actuator 1,1A, IB.

At operation 910, the method may comprise pressing the slide 11 against the trolley line 200 by the at least one actuator 1,1A, IB to form a contact force Fi, F2, Fa between the slide 11 and the trolley line 200.

At operation 920, the method may comprise maintaining the contact force Fi,F2,Fa inside a target range by increasing or decreasing pressure or power of the at least one actuator 1,1A, IB.

Further features of the method directly result from functionalities of, for example, the actuator arrangement. Different variations of the method may be also applied, as described in connection with the various example embodiments.

An actuator arrangement may be configured to perform or cause performance of any aspect of the method (s) described herein.

Any range or device value given herein may be extended or altered without losing the effect sought. Also, any embodiment may be combined with another embodiment unless explicitly disallowed.

Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments . The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages . It will further be understood that reference to ' an ' item may refer to one or more of those items .

The steps or operations of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate . Additionally, individual blocks may be deleted from any of the methods without departing from the scope of the subj ect matter described herein . Aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further embodiments without losing the ef fect sought .

The term ' comprising ' is used herein to mean including the method, blocks , or elements identi fied, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements .

Although subj ects may be referred to as ' first ' , ' second' , or ' third' subj ects , this does not necessarily indicate any order or importance of the subj ects . Instead, such attributes may be used solely for the purpose of making a di f ference between subj ects .

It will be understood that the above description is given by way of example only and that various modi fications may be made by those skilled in the art . The above speci f ication, examples and data provide a complete description of the structure and use of exemplary embodiments . Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments , those skilled in the art could make numerous alterations to the disclosed embodiments without departing from scope of this speci fication .