METHOD FOR PROTECTING A LOADING VEHICLE FROM BEING IMPACTED BY A MINE HOOF DURING A TIPPING OPERATION

Description

TECHNICAL FIELD

[0001] The present application relates to a method of preventing collision of a loading vehicle to a roof of a mine during dumping operation.BACKGROUND OF THE ART

[0002] In mines and other work sites, various loading vehicles are used. The loading vehicle is provided with a boom and a mining work machine, such as a bucket on the boom. Especially in tunnels e.g. in mines and some other kinds of sites, the space above the loading vehicle and the visibility may be limited and there may be a risk that the boom and the bucket may hit a roof of the mine, or another obstacle fastened to the roof, during the movement of the loading vehicle. It may be often difficult for an operator to control the dumping process and move the boom and the bucket to dump a load of the bucket to the dumping target, such as to a box of a dumper truck, in a limited space such as in a mine tunnel. An operator of a loading vehicle may simultaneously actuate an accelerator pedal and control the boom and the bucket manually or semi-automatically for actuating the dumping motion. Controlling the loading vehicle comprising the boom and the bucket may be a demanding task in limited spaces. A method of protecting a loading vehicle according to the prior art is disclosed in documents US2021 / 010234A and US2016 / 123146A.SUMMARY

[0003] According to a first aspect, the present application provides a method of protecting a loading vehicle from hitting a roof of a mine during a dumping operation, comprising steps of: defining a safe space having a safe height from the ground, which safe space is a collision free space for the loading vehicle during the dumping operation, defining at least one reference point of the loading vehicle which is at risk of hitting the roof of the mine during the dumping operation, detecting a dumping motion at a dumping place, wherein material from a bucket of the loading vehicle is removed into a dumping target, allowing motion of the loading vehicle after the dumping motion when each defined reference point is below the safe height.

[0004] The advantage of the method is that risk of collision between the roof of the mine and the loading vehicle may be decreased.

[0005] In an example embodiment of method, motion of the loading vehicle is prevented when at least one defined reference point of the loading vehicle is above of the safe height.

[0006] In an example embodiment of method, motion of the loading vehicle is allowed when each defined reference point is within the safe space.

[0007] In an example embodiment of method, motion of the mining vehicle is prevented when at least one defined reference point of the loading vehicle is outside of the safe space.

[0008] In an example embodiment of method, the reference point of the loading vehicle is the highest point of a bucket or a boom of the loading vehicle during the dumping operation.

[0009] In an example embodiment of method, the safe space is defined by recording a dumping operation and storing the height data of at least one reference point into a control unit.

[0010] In an example embodiment of method, the reference point position during the dumping operation is calculated by using at least one of the following: sensor data provided by at least one angle sensor, the dimensions of the boom, the dimensions of the bucket and the dimensions of the loading vehicle.

[0011] In an example embodiment of method, the reference point position is calculated by using sensor data provided by an angle sensor of the boom.

[0012] In an example embodiment of method, the reference point position is calculated by using sensor data provided by an angle sensor of the bucket.

[0013] In an example embodiment of method, the safe height is the height of the dumping place reduced by a safety margin.

[0014] In an example embodiment of method, the length of the safe space is a distance from a start point of the safe space, wherein the boom or bucket leaves from a transport position for dumping, to a dumping point, in which the dumping motion is performed.

[0015] In an example embodiment of method, a travel distance from the start point of the safe space to the dumping point of the loading vehicle is measured during the dumping operation.

[0016] In an example embodiment of method, several reference points are defined, which reference points of the loading vehicle.

[0017] In an example embodiment of method, the safe space is combination of calculated section of the safe space and recorded section of the safe space.

[0018] In an example embodiment of method, the motion of the loading vehicle is reverse motion.

[0019] It is to be understood that the aspects and example embodiments of the present application described above may be used in any combination with each other. Several of the aspects and example embodiments may be combined together to form a further example embodiment of the present application.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this specification, illustrate example embodiments of the present application and together with the description help to explain the principles of the present application. In the drawings: Fig. 1 shows an example of a dumping site in a mine, Fig. 2 shows an example of a bucket movement and different routes during a dumping operation, Fig. 3 shows an example embodiment of the method, wherein a safe space is defined. Fig. 4 shows an example embodiment of the method, wherein a safe space is defined. Fig. 5 shows an example embodiment of the method, wherein a safe space is defined by recording the movement of the loading vehicle. Fig. 6 shows an example embodiment of the method, wherein a safe space is defined by combining recording and calculation. Fig. 7a and 7b show possible reference points of the boom and the bucket, Fig. 8a and 8b show examples of the boom and the bucket, and Fig. 9 shows a flow chart of the method. DETAILED DESCRIPTION

[0021] A loading vehicle 100 is a machine that is used for collecting material into a bucket 102 and unloading material from the bucket 102 to a target, such as a box of a truck or other target place, with a dumping motion. The loading vehicle 100 comprises a body; a bucket 102 comprising a lip plate and means for measuring a bucket angle b; and a boom 104 having a distal end connected to the bucket 102, a proximal end rotatably supported by the body 101 with a boom joint 105, a boom length L1, a boom position sensor, and a boom angle a. The bucket 102 is rotatably connected to the distal end of the boom 104 by a bucket joint 106, and the bucket 102 has a bucket length L2 between the tip of the lip plate and the bucket joint 106. Further, the loading vehicle 100 comprises a control unit CU, which is configured to control an action of the loading vehicle 100. The loading vehicle 100 may comprise also other structural elements, such as dog bones and swivel levers or arms for controlling the movement of the boom 104 and / or the bucket 102.

[0022] The boom length L1 should be understood as the distance between the bucket joint 106 at the distal end of the and the boom joint 105 at the proximal end of the boom 104.

[0023] The boom angle a is an angle between the horizontal level and the boom 104.

[0024] The bucket angle b is an angle between the horizontal level and bucket length L2, i.e. the line between the bucket joint 106 and the tip of the lip plate 103.

[0025] A dumping operation is a task of a loading vehicle 100, in which the loading vehicle 100, which has arrived at a dumping site, i.e. is at a start point of the dumping operation, is driven near the dumping target while the bucket 102 is lifted and moved above the dumping target for dumping the material. A dumping motion is performed, i.e. the bucket 102 is tilted and the material is removed from the bucket 102, and the loading vehicle 100 and the bucket and the boom are driven back to the start point of dumping operation. Optionally, the material may be removed from the bucket by using a separate ejector plate.

[0026] A safe space should be understood as a collision free space for the loading vehicle during the dumping operation, i.e. a space in which a bucket and a boom may move freely without risk of hitting the roof of the mine. The safe space may be for example cubic-shaped area, or it may be three-dimensional area having irregular shape, or any other shape that may be defined. The safe space may be divided into sections and the dimensions and shapes of the different sections may be defined together or they may be defined independently, i.e. separately using different methods. Further, the different sections may have different shapes.

[0027] A start point of the safe space means a position of the loading vehicle, wherein the bucket and the boom leave from a transport position, i.e. are lifted from the lowest or near the lowest position for dumping. Optionally or additionally, the start point of the safe space is a position where one of the reference points exceeds a height limit, that may be determined by a parameter (e.g. a distance from the ground). The start point of the safe space may be used for example as a starting point of recording the safe space.

[0028] Figure 1 shows an example of a dumping site 1, which comprises a roof 2 and a dumping target 3. The dumping site is usually higher than the tunnel leading to the dumping site. Thus, the loading vehicle is able to lift the bucket up and empty the material from the bucket to the dumping target, which may be above the ground. The dumping target may be for example a truck. Dumping site may have the same height as the tunnel leading to the dumping site.

[0029] Figure 2 shows an example of the bucket movement and possible routes (dashed lines) during the dumping operation. The bucket 102 is at its lowest position when the loading vehicle arrives to the dumping site 1. Once the dumping operation is started, the bucket is lifted, and the loading vehicle is driven forward so that the bucket is above the dumping target 3. Once the bucket 102 is above the dumping target 3, the dumping motion is enabled and the material from the bucket is removed to the dumping target. During the dumping operation, the loading vehicle, especially the bucket or the boom, may collide with the roof 2. Figure 2shows some examples of collision points 4a, 4b, 4c, 4d,...

[0030] Figure 3 shows a side view of an example of a method of protecting a loading vehicle 100 from hitting a roof 2 of a mine, especially at dumping site 1, during a dumping operation. In the method, a safe space 110 having a safe height SH from the ground is defined. In figure 3, the safe space is formed from two sections 111 and 112. In this example embodiment, the safe space 110 is defined by using measured, defined or calculated parameters of the dumping site and / or the loading vehicle. The first section 111 of the safe space is defined as an area at the dumping site 1, and the second section of the safe space 112 is defined as a section extending from the dumping site 1 into the tunnel leading to the dumping site. The height of the second section of the safe space 112 may be for example the height of the bucket and the material in the bucket at the start point of the safe space. Together these two sections form the safe space 110, in which the loading vehicle may operate safely. The safe height SH of the safe space 110 may be different in different sections of the safe space. Also, the safe height may vary in different places of the dumping site and / or in different places within the sections of the safe space. The safe space may extend over the dumping target as shown in figure 3. The safe space dimensions may be calculated based on the dimensions of the dumping site.

[0031] For preventing the collision, i.e. hitting the roof, the movements of the loading vehicle must be known. Especially, when preventing collision with the roof, one must know the positions of the points, which are at risk of hitting the roof. Those points are referred as reference points herein. Therefore, at least one reference point of the loading vehicle is defined. The reference point is a point of the loading vehicle, which is at risk of hitting the roof of the mine during the dumping operation.

[0032] The reference point may be any point of the loading vehicle 100. It may be only one refence point that is defined or, optionally, several reference points are defined. Usually, during the dumping operation, several parts of the loading vehicle may be at risk of hitting the roof of the mine. Especially, the highest point of the loading vehicle is at great risk of hitting the roof. The highest point of the loading vehicle may vary during the dumping operation depending on the phase. The reference point may be for example the tip of the lip plate of the bucket, bucket joint, other part of the bucket, distal end of the boom, or other part of the boom. Another high collision risk point of the loading vehicle is the furthest point in horizontal level, i.e. the point that is extending furthest from the body. For example, the furthest point may be the tip of the bucket, which is at risk at hitting obstacles when driving forward.

[0033] During the dumping operation, the dumping motion at the dumping place is detected. For example, the dumping motion may be detected if the bucket angle reaches a certain value. E.g. tip of the bucket is lowered by increasing the bucket angle towards the ground in relation to the horizontal level, the material from the bucket falls off from the bucket into the dumping target, i.e. dumping occurs. Optionally, the dumping motion may be detected if an ejector plate is used for removing the material from the bucket.

[0034] After the dumping motion, the loading vehicle should be driven back to the start point of the safe space.

[0035] Therefore, the loading vehicle is put into a motion, which may include moving the bucket, the boom, and / or the loading vehicle as a whole. As the mine, e.g. the dumping site and the tunnel, have limited free space, there is a risk that some part of the loading vehicle could collide with the roof of the mine. To prevent the collisions, motion of the loading vehicle is allowed when the loading vehicle, and the parts of the loading vehicle, are not at risk at colliding with the roof of the mine.

[0036] Usually, the loading vehicle is reversed to the start point of the safe space and the boom and the bucket are also moved, i.e. lowered, to the transport position (lowest or near the lowest position) during the reverse motion of the loading vehicle. During the dumping motion, the bucket is in lifted position so that the material may be dumped into the dumping target, e.g. box of a truck. If the loading vehicle is driven, e.g. reversed, back to the start point of the safe space, and the bucket and / or the boom is not lowered to the transport position at the same time, the lifted parts (bucket and / or boom) of the loading vehicle most likely will hit the roof. To prevent this, the movement of the lifted parts during the movement of the loading vehicle from the dumping point to the start point of the safe space is controlled and the motion of the loading vehicle is allowed only if each of the defined reference points is below the safe height of the safe space. Optionally, motion of the loading vehicle is allowed if each defined reference point is within the safe space. Optionally, if at least one of the defined reference points is above the safe height of the safe space or, optionally, each reference point is outside of the safe space, the motion of the loading vehicle is prevented. Motion of the loading vehicle may be reverse motion of the loading vehicle. Optionally or additionally, motion of the loading vehicle includes the motion of the boom and / or the bucket, which may be prevented if the motions would lead to a collision with the roof, e.g. lifting movement may be restricted after the dumping motion and before the reverse motion has started, and / or during the reverse motion, i.e. once the reverse motion has started and before the loading vehicle has stopped. Optionally or additionally, lowering motion of the bucket and / or the boom is allowed when at least one reference point is above the safe height or outside of the safe space. With such an arrangement, the bucket and / or the boom may be lowered from the risk zone to the safe zone, i.e. below the safe height, for operating safely. Optionally or additionally, lifting motion of the bucket and / or the boom is prevented when at least one reference point is above the safe height or outside of the safe space.

[0037] The reference point of the loading vehicle may be the highest point of a bucket or a boom of the loading vehicle during the dumping operation. Optionally, the reference point may be the furthest point (in horizontal level) of the loading vehicle, e.g. the tip of the bucket during forward motion of the loading vehicle. The reference point, which is at risk of collision, of the loading vehicle may vary during the dumping operation and, thus, several reference points may be defined.

[0038] Figure 4 shows a side view of another example embodiment of the method. In this example embodiment, the dimensions of the first section 111 of the safe space 110 is defined by using measured, defined or calculated parameters of the dumping site and / or the loading vehicle. The safe space in figure 4 is from the dumping target to a certain distance from the dumping target, which distance is defined by using the dimensions of the dumping site. The second section 112 of the safe space extends from the dumping site into the tunnel leading to the dumping site. The height of the second section 112 is max. the height of the tunnel or, preferably, less than the height of the tunnel. Both of the sections are cubic-shaped areas.

[0039] It should be noted that, optionally, the safe space may be only one cubic-shaped area having a safe height SH and length. For example, the safe space 110 may be an area like the first section 111 of the safe space in figure 3 or 4.

[0040] Figure 5 shows a side view of an example embodiment of the method, wherein the safe space 110 is defined by recording the first dumping operation, especially the forward motion from the start point (lifting of the boom and / or bucket is started) to the dumping point, and storing the position data of at least one reference point into a control unit CU. The safe height SH may be for example the path of the highest point of the loading vehicle 100 during the dumping operation. The safe height SH may follow the shape of the roof 2 of the dumping site 1. Optionally, the safe space 110 is defined for each dumping operation separately. Especially, each forward motion from the start point (lifting of the boom and / or bucket is started) to the dumping point is recorded for defining the safe space so that the loading vehicle may reverse back from the dumping point to the start point of the safe space, including the movement of the bucket and the boom, safely following the recorded route. By using recorded safe space, the safe space may not necessarily have any specific start point of end point in the direction of the loading vehicle movement. Only safe height is defined and recorded during a dumping operation. Optionally, length of the safe space is defined being from the start point of the dumping operation, where the lifting of the bucket and / or boom is started, to the dumping target.

[0041] The reference point position during the dumping operation may be calculated by using at least sensor data provided by at least one angle sensor, the dimensions of the boom, the dimensions of the bucket and the dimensions of the loading vehicle. The reference point position may be calculated by using sensor data provided by an angle sensor of the boom and / or the angle sensor of the bucket. Optionally or additionally, the dimensions of the dumping site may be used for calculating or defining the safe space. Optionally or additionally, the bucket angle may be calculated by using the position of the bucket and the boom cylinder, fastening points of the bucket and boom cylinder, dimensions of the boom, the bucket and levers (such as dog bone and swing lever). The left side of the safe space (as seen in the figures and it should be understood that the left side may be the right side if the loading vehicle approach the dumping target from other direction) may be the location where the loading vehicle is after dumping motion and when the reverse motion is enabled, and the right side (as seen in figures) may be the location where the loading vehicle has reversed certain distance, which have been defined by the parameters.

[0042] Figure 6 shows a side view of an example embodiment of the method, wherein the second section 112 of the safe space 110 is defined by recording the first, or each, dumping operation, optionally only from start (when the bucket and / or boom lifting is started) to the dumping point, i.e. the forward movement, and storing the position data of at least one reference point into a control unit CU. The first section 111 of the safe space 110 is calculated using the dimensions of the dumping site or desired safe space, or other parameters as described above. The safe space is a combination of the first section 111 and the second section 112. The length of the safe space may be determined by the parameters, such as dimensions of the dumping site and / or the loading vehicle. Optionally or additionally, the starting point of the dumping operation is used as a starting point of the safe space and / or the dumping target is used as an end point of the safe space.

[0043] The bucket angle sensor may be for example inclinometer. Optionally or additionally, a linear position sensor (e.g. cylinder sensor) is used for determining the bucket angle. Optionally or additionally, the bucket angle may be calculated by using geometry of the boom 104 and / or the bucket 102, and / or the location of the cylinder or cylinders moving the boom and / or bucket. For example, the distance of the cylinder movement may be measured, and that distance data may be used for defining or calculating the boom angle and / or bucket angle. The fastening points of the cylinder or cylinders are known and the fastening point locations may be used for defining or calculating the boom angle and / or bucket angle. Optionally or additionally, other parameters may be used for defining or calculating the boom or bucket angle. E.g. the loading vehicle may comprise levers or such for moving the boom and bucket and possible lever dimensions and fastening points may be used for defining or calculating the boom angle and / or the bucket angle.

[0044] Figure 7a and 7b shows examples of the reference points 200a, 200b, 200c, 201a, 201b, 201c, 201d, 201e, 201f. In figure 7a shows examples of reference points 200a,... of the boom 104. Possible reference points may be for example the distal end of the boom 200a or upwards extending points 200b, 200c. Figure 7b shows examples of the reference pints 201a,... of the bucket 102. Possible reference points may be for example, the tip of the bucket 201a, the top points 201b, 201c, the back points 201d, 201e, or heel 201f. Positions of the reference points may be calculated by using the dimension of the boom and / or bucket and the dimension of the loading vehicle, e.g. the height of the boom joint 105, boom angle, bucket angle. The boom angle may be determined by using a boom position sensor, such as an angle sensor, which indicates the angle variations of the boom 104. Optionally, an inclinometer may be used for determining the boom angle. Optionally, the bucket angle and / or the boom angle may be determined by calculating bucket cylinder or boom cylinder position, i.e. the distance of the piston movement in the cylinder. Other parameters that may be used for calculating the reference point position may be for example, the reference point(s) of the bucket 102, i.e. the possible highest point(s) of the bucket 102, geometry of the bucket 102, swivel arm of the bucket 102, any levers supporting the bucket 102 to the boom 104 or vehicle body 101 and loading vehicle 100 dimension (e.g. height of the boom joint 105).

[0045] Figures 8a shows an example of a boom of the loading vehicle and figure 8b shows an example of a bucket of the loading vehicle. The boom 104 has a length L1 which is a distance between a boom joint 105, at which the boom is rotatably connected to the body of the loading vehicle, and a bucket joint 106, in which the bucket is rotatably connected. The boom angle a is an angle between an axis of the boom, between the boom joint and the boom joint, and the horizontal level. The bucket angle b is an angle between an axis, extending between the bucket joint and the reference point of the bucket (e.g. tip of the bucket 201a in figure 8b), and the horizontal level.

[0046] The safe height SH of the safe space may be for example the height of the dumping place reduced by a safety margin. The height of the dumping place may be measured any time before or during the dumping operation or the information may be retrieved from other data source, e.g. mine drawings etc. The safety margin may be for example 10 cm, 20 cm, 50 cm or 100 cm or any range between said values.

[0047] The length of the safe space, i.e. the measurement in direction of the loading vehicle movement, may be for example a travel distance from the start point of the safe space to the dumping point of the loading vehicle. The distance from the start point of the safe space to the dumping point may be measured by using a travel counter or other means suitable for measuring distance. The travel distance may be measured during the movement from the start point of the safe space to the dumping point. Optionally, the length of the safe space may be defined by using parameters as described earlier.

[0048] Figure 9 shows a flow chart of the method.

[0049] In each example embodiment, the safe height SH should be understood as a level of height having a risk-free zone, i.e. the safe space, below it for the loading vehicle to operate. In other words, the area above the safe height SH is a risk zone where the loading vehicle is at risk of colliding with the roof of the mine.

[0050] Below the safe height SH of the safe space, there may be a margin zone, i.e. certain distance to the safe height. When the loading vehicle, or parts of the loading vehicle, enters the margin zone, the speed of the motion of the loading vehicle is reduced before reaching the safe height of the safe space. Thus, the motion of the loading vehicle is not rapidly stopped once it reaches the safe height. Additionally or optionally, the horizontal ends of the safe space, i.e. the start point and the end point in lateral level, may comprise similar margin zones, wherein the speed of the loading vehicle, or parts of the loading vehicle, is reduced before reaching the start point or the end point.

[0051] Although the present application has been the described in conjunction with a certain type of device, it should be understood that the present application is not limited to any certain type of device. While the present application has been described in connection with a number of exemplary embodiments, and implementations, the present application is not so limited, but rather cover various modifications, and equivalent arrangements, which fall within the purview of prospective claims.

Claims

1. Method of protecting a loading vehicle (100) from hitting a roof (2) of a mine during a dumping operation, comprising steps of: - defining a safe space (110) having a safe height (SH) from the ground, which safe space is a collision free space for the loading vehicle during the dumping operation, - defining at least one reference point (200a, 200b,..., 201a, 201b,...) of the loading vehicle, - detecting a dumping motion at a dumping place (1), wherein material from a bucket of the loading vehicle is removed into a dumping target (3), - allowing motion of the loading vehicle after the dumping motion when each defined reference point is below the safe height.

2. The method according to claim 1, wherein motion of the loading vehicle is prevented when at least one defined reference point of the loading vehicle is above of the safe height.

3. The method according to 1 or 2, wherein motion of the loading vehicle is allowed when each defined reference point is within the safe space.

4. The method according to any one of claims 1 to 3, wherein motion of the mining vehicle is prevented when at least one defined reference point of the loading vehicle is outside of the safe space.

5. The method according to any one of the preceding claims, wherein the reference point of the loading vehicle is the highest point of a bucket (102) or a boom (104) of the loading vehicle during the dumping operation.

6. The method according to any one of the preceding claims, wherein the safe space is defined by recording a dumping operation and storing the height data of at least one reference point into a control unit (CU).

7. The method according to any one of the preceding claims, wherein the reference point position during the dumping operation is calculated by using at least one of the following: sensor data provided by at least one angle sensor, the dimensions of the boom (104), the dimensions of the bucket and the dimensions of the loading vehicle.

8. The method according to claim 7, wherein the reference point position is calculated by using sensor data provided by an angle sensor of the boom (104).

9. The method according to claim 7 or 8, wherein the reference point position is calculated by using sensor data provided by an angle sensor of the bucket.

10. The method according to any one of the preceding claims, wherein the safe height (SH) is the height of the dumping place (1) reduced by a safety margin.

11. The method according to any one of the preceding claims, wherein the length of the safe space is a distance from a start point of the safe space, wherein the boom or bucket leaves from a transport position for dumping, to a dumping point, in which the dumping motion is performed.

12. The method according to claim 11, wherein a travel distance from the start point of the safe space to the dumping point of the loading vehicle is measured during the dumping operation.

13. The method according to any one of the preceding claims, wherein several reference points are defined, which reference points are in different locations of the loading vehicle.

14. The method according to any one of the preceding claims, wherein the safe space is combination of calculated section of the safe space and recorded section of the safe space.

15. The method according to any one of the preceding claims, wherein the motion of the loading vehicle is reverse motion.