WO2013098460A1

WO2013098460A1 - Method and mining vehicle for post-drilling insertion

Info

Publication number: WO2013098460A1
Application number: PCT/FI2011/051161
Authority: WO
Inventors: Federico Scolari
Original assignee: Sandvik Mining And Construction Oy
Priority date: 2011-12-28
Filing date: 2011-12-28
Publication date: 2013-07-04
Also published as: SE1450818A1

Abstract

The invention relates to a method and a mining vehicle for post drilling insertion. A mining vehicle (1, 16) includes at least one boom (5b) provided with a post-drilling unit (17) for feeding an insertion object (26) into a pre-drilled hole (7). During drilling positioning data of the hole is gathered and stored in a control unit (12, 13). The stored positioning data is used when rough positioning the post-drilling unit in a vicinity of the pre-drilled hole. The positioning also comprises a fine positioning wherein the hole collar is detected and the insertion device is driven from the vicinity to the collar.

Description

Method and mining vehicle for post-drilling insertion

Background of the invention

The invention relates to method for post drilling insertion, wherein an elongated insertion object is fed into a pre-drilled hole. The feeding is per- formed by means of an insertion unit, which is arranged to a free end of a boom that belongs to a mining vehicle. The insertion object is pushed to the pre-drilled hole at least partly.

The invention still further relates to a mining vehicle.

The field of the invention is defined more specifically in the pream- bles of the independent claims.

Rock may be excavated in so called rounds. This means that drill holes are first drilled in rock, after which the drill holes are charged and blasted. Rock material becomes detached from the rock by the amount of the volume of the round, and it is transported elsewhere before drilling the next round. Various tunnels, underground storage halls, containers, parking spaces or other corresponding rock caverns may be formed in the rock by excavation. However, the rock in which such rock caverns are excavated is not always sufficiently firm, uniform and stable by nature. Also, blasting a round may break or otherwise weaken the rock defining the rock cavern, so that the firmness of the rock is insufficient after excavation. Thus, it is rather typical that the ceiling and walls of the rock cavern, sometimes even the floor, must be reinforced. Reinforcing may be done by drilling to the rock several reinforcement holes in which a rock bolt, a cable or the like reinforcement member or reinforcement material is fitted.

The reinforcement holes may be drilled beforehand by using a rock drilling rig provided with a drilling unit. After the drilling the rock bolt is mounted in the pre-drilled hole by a post-drilling vehicle equipped with an insertion device. It has been found difficult to position the insertion unit to the pre-drilled hole for insertion. Brief description of the invention

An object of the invention is to provide a novel and improved method and a mining vehicle for inserting objects into pre-drilled drill holes.

The method according to the invention is characterized by implementing in the positioning of the post-drilling unit two consecutive positioning steps having differing control principles; rough positioning the post-drilling unit at a proximity of a collar of the pre-drilled hole according to the position data stored in the control unit; determining after the rough positioning the position of the collar of the pre-drilled hole relative to the post-drilling unit by means of at least one sensing unit arranged in the post-drilling unit and producing sensing data; and fine positioning the post-drilling unit to the collar of the pre-drilled hole according the sensing data.

The mining vehicle according to the invention is characterized in that the control unit comprises a control strategy for controlling the positioning of the post-drilling unit according to consecutive rough positioning and fine po- sitioning, and wherein the rough positioning is based on the data element including position data; the post-drilling unit comprises at least one sensing unit for producing position data of the collar of the pre-drilled hole; and wherein the control unit is arranged to fine position the post-drilling unit according to the sensed position data.

An idea is that the drilling unit and the post-drilling unit are in different booms and that positioning of the post drilling unit to a pre-drilled hole includes two phases, namely a rough positioning and a fine positioning. At first one or more drill holes are drilled with the drilling unit. For example coordinates and directional angles of the holes may be stored during drilling. Thereafter the post-drilling unit or an insertion unit is positioned to the pre-drilled hole for the insertion. The positioning of the post-drilling unit comprises two consecutive positioning steps having differing control principles. Thereby the post-drilling unit is at first rough positioned in a vicinity of a collar of the pre-drilled hole. The rough positioning is based on position data stored in one or more control unit during the positioning of the drilling unit or during the drilling. Alternatively the rough positioning can be based on position data defined in a drilling plan or drilling pattern. After the post-drilling unit is rough positioned the position of the collar of the pre-drilled hole is determined. The collar is determined by one or more sensing unit, which is arranged in the post-drilling unit. The sensing unit produces sensing data, which is used in a fine positioning phase. In the fine positioning the post-drilling unit is positioned to the collar of the pre-drilled hole according to the determined sensing data of the pre-drilled hole. In the fine positioning the post-drilling unit can be positioned to the pre-drilled hole so that it is possible to feed a front end of the insertion object into a hole collar.

An advantage of the disclosed solution is that the positioning of the post-drilling unit can be fast and effective. The stored positioning information allows the fast rough positioning. In the rough positioning the post-drilling unit can be moved close to the pre-drilled hole using fast movements since there is no need for final accurate positioning in the first positioning step. On the other hand, in the fine positioning step the accurate position of the collar of the pre- drilled hole is searched and the post-drilling unit is positioned accurately to the right position for the insertion. In the fine positioning the positioning movements may be delicate and slow but at the same time there is a need to move the post-drilling unit only a relatively short distance, whereby the fine positioning takes only a short time. Further, at least the rough positioning of the post- drilling unit can be executed without any fixed infrastructure or aid means outside the mining vehicle. One more benefit is that the positioning system is fully operable also in underground mines and working sites wherein normal positioning systems, such as GPS positioning, does not work.

According to an embodiment the position of the drilling unit is de- termined by means of one or more sensors arranged in a drilling boom, and correspondingly the position of the post-drilling unit in rough positioning is determined by means of one or more sensors arranged in a post-drilling boom. The sensors may be arranged in joints or elsewhere in the booms. Thus, in this embodiment the rough positioning of the boom is based on measuring or sens- ing information received from one or more boom sensors and calculations executed in a control unit of the mining vehicle.

According to an embodiment the position of the drilling unit and the post-drilling unit is determined by utilizing electromagnetic radiation. Thereby a laser measuring system can be used for example. In the laser measuring sys- tern a laser beam can be transmitted from a measuring device arranged on the carrier and the boom or the operating unit in the boom may be provided with a reflector, for example. Alternatively the positioning can be based on wireless positioning utilizing electromagnetic waves such as radiofrequency waves. In such positioning a wireless network is formed between at least three base sta- tions, suitable transmitters or transceivers. In this embodiment the booms are not necessarily equipped with positioning sensors. However, it is possible to combine the sensors and electromagnetic wave positioning system too.

According to an embodiment the position of the drilling unit and the post-drilling unit is determined by utilizing ultrasonic sound. Sound transmitters and receivers can be arranged on the carrier of the mining vehicle and to the booms. The control unit is arranged to calculate the position and direction of the boom on the basis of the sound detection and kinematics of the boom.

According to an embodiment a hole recognition system is applied in the fine positioning. The post-drilling unit is provided with one or more cameras for producing image data on a rock surface close to the rough positioned post- drilling unit. Further, the control unit of the mining vehicle executes the hole recognition program to identify the pre-drilled hole in the rock surface on the basis of the image data. The hole recognition system detects accurate position of the pre-drilled hole and control commands are given to actuators of the post- drilling boom to implement the fine positioning. In addition to the camera, the post-drilling unit may be equipped with another type of detector to detect or measure the accurate position of the hole mouth. An advantage of this embodiment is that the accurate position of the pre-drilled hole can be found fast and reliably. The detection can be made without any fixed infrastructure and aid means arranged in the rock surface. Let it be mentioned that the hole recognition system may comprise two or more digital still cameras or video cameras in order to improve the detection. Stereo vision may be beneficial for the control of the fine positioning.

According to an embodiment one or more identifiers are arranged in connection with at least one drilled bore hole in order to facilitate positioning of devices used in the post-drilling phases. The post-drilling unit may be provided with means for reading or identifying the identifier placed into the drill hole or near the mouth of the borehole. The drilling unit may be provided with a mounting or applying device for arranging the identifier at the drill hole before starting the drilling operation, during the drilling operation or directly after the drilling. The identifier is installed before the drilling unit is moved away from the drilled hole towards the next drill hole position. The use of the identifier fastens and simplifies the positioning of the post-drilling units and devices and makes the positioning accurate too.

According to an embodiment one or more drilled hole is provided with one or more physical identifier piece. The identifier may be a tubular piece, which can be partly inserted in a borehole, for example. The identifier improves detection of the drilled hole. The identifier may have a colour or a shape that is easier to detect by means of a camera. The identifier piece may form a sharp edge for the drill hole, which improves detection of the hole by optical means. Furthermore the identifier may comprise a transmitter and the post-drilling device may comprise a receiver whereby a wireless data connection can be created between the identifier and the insertion device. The data transmission can be used for positioning the post-drilling units accurately to the pre-drilled hole. The identifier may comprise a RFID (Radio Frequency IDenti- fication) tag, for example.

According to an embodiment one or more pre-drilled hole is provided with one or more colour medium. Around the drilled hole a colour marking can be painted. The marking may have an annular shape. The drilling unit may be provided with a spraying device or nozzle for applying the colour medium to the drill hole collar. The colour medium can be selected so that the pre-drilled hole can be detected more easily with an optical hole recognition system comprising one or more cameras and a computer vision system. Thanks to the painted marking influence of shadows and surface irregularities can be diminished. One possibility is to use reflecting paint or electromagnetic waves emit- ting paint and to provide the insertion unit with a light source or another suitable emitter. The computer vision system executes an image processing for digital images taken by a digital camera arranged in the post-drilling unit. The image processing can be based on feature detection and feature extraction. As a result of the image processing accurate position of the pre-drilled hole can be automatically detected and control commands can be formed in a control unit of the mining vehicle for controlling boom actuators. The identifier according to this embodiment can radically improve efficiency of the optical hole recognition. Painted identifier is also easy to apply, inexpensive and endures well in demanding conditions.

According to an embodiment colour medium is fed through a drilling tool in order to make a position identifier to the rock surface. The colour medium can be fed via normal flushing channels to a drill bit wherefrom the colour medium spreads to surrounding surfaces. An advantage of this embodiment is that no separate paint system needs to be arranged in the drilling unit.

According to an embodiment colour medium is fed through a drill bit after being extracted from the drill hole. Thereby a painted ring is formed around the drill hole opening. This improves optical detection of the edge of the drill hole opening. If desired, the paint inside the hole can be removed by reinserting the drill bit inside the drill hole and feeding flushing water through the drill bit to the drill hole whereby the paint is flushed away from the inside surfaces of the drill hole. When the paint is removed inside the hole the edge detection of the drill hole opening is improved since the drill hole shows as a dark circle, which is surrounded by the colour marking. The colour medium can be chosen so that a clear contrast occurs between the dark circle and the annular paint marking.

According to an embodiment two or more different colours are used for marking the drilled holes. The above disclosed physical identifier piece or painted marking may have a colour code system wherein different colours may indicate rock features such as rock stability, fractured rock or voids in rock. Hazardous drill holes can also be provided with a specific colour code. Information for the colour code system can be gathered during the drilling manually by the operator of the rock drilling rig and automatically by means of sensors and a drilling monitoring system.

According to an embodiment the positioning of the post-drilling unit comprises a third positioning step, which is executed after the fine positioning. In the third step the feeding angle of the insertion object is changed simultaneously with the insertion. In this embodiment the actual directional angle of the pre-drilled hole can be searched. A front end of the insertion object can be kept stationary in a transverse direction during the change in the feeding angle. Thereby the change in the feeding angle is performed relative to the front end. Further, the adjustment of feeding angle can be set to be proportional to the feeding distance, whereby the adjustment has a greater magnitude at first and when feeding proceeds, the angle adjustment decreases. The change in the feeding angle can be put into practice by rotating or turning a rear end of the feed beam of the insertion unit along a curved path of movement by means of an angle adjusting device. An advantage of this embodiment is that a solution is presented to the possible miss-alignment problem between the pre-drilled hole and the insertion object. Moreover, the embodiment may also solve hole irregularity problems occurring in the insertion procedure since the feeding angle adjustment may facilitate penetration of the insertion object to the pre- drilled hole.

According to an embodiment the mining vehicle is a multi-use vehicle being capable of drilling and insertion operations. Such a mining vehicle is provided with at least two booms wherein at least one first boom is a drilling boom provided with a drilling unit and at least one second boom is a post- drilling boom provided with a post-drilling unit. In this embodiment the needed drilling and post-drilling operations are executed by the same mining vehicle the carrier of which is not moved between the operations. The mining vehicle is positioned and navigated to the mining working site only once, which minimizes the carrier positioning measures.

According to an embodiment the mining vehicle is a post-drilling ve- hide without any drilling unit. Such a mining vehicle is a special-purpose vehicle equipped only for feeding insertion objects into the pre-drilled holes. Construction and control of such special mining vehicle can be optimized according to one purpose only.

According to an embodiment the mining vehicle is positioned to a mining working site by means of a distance measurement based on dead reckoning.

According to an embodiment the positioning of the mining vehicle to a mining working site is at least mainly based on a distance measurement utilizing dead reckoning.

According to an embodiment rock surfaces around the mining vehicle are scanned and the scanning data is used when positioning the mining vehicle to a mining working site.

According to an embodiment the positioning of the mining vehicle to the working site is based on fixed position identifiers in the mine or peg num- bers of the mine identifying mine distances, locations and layers.

According to an embodiment the positioning of the mining vehicle to the working site is based on positioning in a wireless network. The wireless network may include several base stations or beacons.

According to an embodiment the positioning of the mining vehicle to the working site is based on tachymeter measuring.

According to an embodiment the positioning of the mining vehicle to the working site is based on laser measuring. Relative distance and direction of the mining vehicle to a reference point can be measured and the positioning can be calculated on the basis of the measuring data. A so called total station measuring device and principle can be used.

According to an embodiment the mining vehicle is positioned automatically to a mining work site under control of the control unit of the mining vehicle or mine control unit.

According to an embodiment the disclosed post-drilling measures are executed automatically under control of the control unit of the mining vehicle. According to an embodiment the pre-drilled hole is a reinforcing hole. In this case the insertion object may be an elongated physical piece such as a rock bolt, tube or cable that is pushed into the drill hole. Alternatively the insertion object may be a feed hose, tube or channel that can be partly pushed into the drill hole where after reinforcing injection material or grouting material such as a concrete or any other soldering material can be fed through the hose inside the drill hole. Thereby the insertion object may be a reinforcing piece or feeding means for feeding material into the hole.

According to an embodiment the pre-drilled hole is a blasting hole. In a post-drilling phase an explosive is fed to the drill hole. The explosive can be in a form of a powder or granules whereby it can be fed into the drill hole by means of an elongated feed hose, tube or channel pushed at least partly inside the drill hole. Further, it is possible to use explosive cartridges or packages, which can be pushed to the drill hole by means of an elongated bar. More- over, in a small-charge-blasting mining method propellant charges are fed into the drill hole through an elongated hose or tube. Thereby the insertion object may be an elongated explosive package or feeding means for blasting or propellant material.

According to an embodiment in the post drilling phase an elongated measuring probe is fed into the drill hole. Thereby the insertion object may be a sensing or measuring instrument. The inserted instrument can be used for confirming that the drilling accuracy is according to the drilling plan. It is possible to measure direction of the pre-drilled hole and bottom coordinates of the pre-drilled hole, for example. Brief description of the figures

Some embodiments are described in closer detail in the accompanying drawings, in which

Figure 1 shows schematically a rock drilling rig positioned in the face of a rock cavern for drilling reinforcement or blasting holes,

Figure 2 shows schematically a perspective view of a tunnel having blasting holes and a reinforcement fan,

Figure 3 shows schematically and seen from above an embodiment wherein a separate drilling vehicle and post-drilling vehicle are used,

Figure 4 shows schematically and seen from above an embodiment wherein a mining vehicle includes a drilling boom and a post-drilling boom,

Figure 5 shows schematically a post-drilling unit, Figures 6a - 6c show schematically an insertion cycle comprising feed and feed angle adjustment and possible other feeding aid measures,

Figure 7 schematically shows a rock surface area wherein drill holes are drilled and some of the openings of the drill holes are provided with a posi- tioning aid,

Figure 8 is a simplified chart showing some features disclosed in this application.

For the sake of clarity, the figures show some embodiments of the invention in a simplified manner. In the figures, like reference numerals identify like elements.

Detailed description of some embodiments

Figure 1 shows a rock drilling rig 1 navigated in a face 3 of a tunnel 2 or the like rock cavern. The rock drilling rig 1 comprises a movable carrier 4 provided with one or more drilling booms 5, each of which has a rock drilling unit 6 at its outermost end. The drilling unit 6 may be positioned at a start location of a drill hole 7 by moving the boom 5. Drill holes 7 can be drilled for a round 8 and for a reinforcement fan 9. When the rock drilling rig 1 is driven to the drilling location, navigation is first carried out in which the coordinate system of the drilling rig is connected to the coordinate system of the working site. The actual drilling cycle is performed for each drill hole after the drilling unit 6 has first been positioned in the start location and direction determined by the drilling pattern or controlled by an operator manually. The control system may comprise one or more control units 12, which may be a computer or a processor capable of determining the actual position of the boom. The boom 5 may comprise two or more boom parts connected to each other by means of joints. In the boom 5, there may be sensors 1 1 or the like measuring devices, and on the basis of the position information obtained from them, the control unit 12 can determine the location and direction of the drilling unit 6. The positioning data of each hole 7 being drilled is stored and can be utilized in post-drilling actions such as in reinforcement or explosive insertion. Information can be gathered also during the drilling utilizing a so called measuring while drilling system. This hole specific information can be utilized in post-drilling measures too. The drill hole data can be transmitted to a control unit 13 of a mine or directly to a control unit of a second mining vehicle comprising post-drilling inser- tion means. In Figure 1 , the drilling unit 6 is positioned at the point of an excavation drill hole 7a to be drilled. The tunnel 2 is excavated by drilling in the face 3 several excavation holes 7a substantially in the direction of a tunnel line L, which are charged with explosives after the drilling. At least position infor- mation of such blast holes 7a are saved for post-drilling charging. In blasting, rock material is detached from the rock by the volume of the round 9. Blasting a round may damage the rock defining the tunnel contour, or the firmness of the rock may be insufficient by nature in order to guarantee a safe tunnel. Thus, there may be a need to reinforce the ceiling 14 and walls 15 of the tun- nel 2. The rock may be reinforced by drilling, several adjacent reinforcement holes 7b to which a rock bolt or the like reinforcement members can be fitted. The number, depth, diameter, start locations and directions of reinforcement holes 7b among other drilling information may be stored in a memory media and can be used in post-drilling reinforcement insertion. The obtained rock quality related information can be used to determine installation pressure of an expandable rock bolt for example. The reinforcement holes 7b may be drilled in a fan form, whereby there are drill holes on both walls 15 and on the ceiling 14 of the tunnel. The direction of the reinforcement holes 7b is crosswise to the tunnel line L.

In Figure 2 it is illustrated a tunnel 2 having blast holes 7a for excavating a round 8 and a reinforcement fan 9 provided with several reinforcement holes 7b. In a post-drilling phase insertion objects can be inserted into these pre-drilled holes 7 by means of an insertion unit arranged in a post-drilling boom. Charges such as explosives or propellants can be inserted into the blast holes and reinforcing members such as rock bolts or injection material or grouting material can be inserted into the pre-drilled holes.

Figure 3 shows an arrangement wherein drilling is performed by a mining vehicle 1 having one or more drilling booms 5a provided with drilling units 6, and for the post-drilling operation there is a special post-drilling mining vehicle 16 having one or more post drilling booms 5b provided with insertion units 17. At first a rock drilling rig 1 is positioned to a drilling site and planned holes 7 are drilled. Thereafter the post drilling mining vehicle 16 is positioned to the drilling site and insertion objects are fed into the pre-drilled holes 7. Coordinates, directional angle and other positioning information is stored during the drilling phase and the positioning information can be communicated from the control unit 12 of the rig 1 to a mine control unit 13 and to a control unit 18 of the post-drilling mining vehicle 16. Thereby positioning information gathered during drilling can be utilized in positioning the insertion unit 17 at the pre- drilled hole.

The positioning of the mining vehicles 1 , 16 to the working site can be based on fixed position identifiers 19, scanned wall surface profiles 20 of the working site, distance measurement based on dead reckoning, peg numbers 21 identifying mine distances, positioning based on wireless beacons, or their combination. Furthermore, in positioning a tunnel laser 22 may also be utilized. After the positioning the mining vehicle is navigated so that one united coordinate system is used in drilling and post-drilling actions. At least the position of each drilled hole is stored when the drilling unit is positioned and drilling is started. Thereby coordinates of the drilled holes are known by the positioning system. Positioning data can be stored and managed by using a standardized format, such as IREDES (International Rock Excavation Data Exchange System), whereby data is compatible for different control units involved. The positioning information is communicated to the post-drilling mining vehicle 16, which is positioned and navigated to the working site where the pre-drilled holes are located. The post-drilling unit or insertion unit 17 is positioned according to the stored drill hole position information close to the pre-drilled hole 7. Since there may be inaccuracy in the positioning because of clearances of the boom joints, it may be impossible or difficult to position the insertion unit 17 directly to a collar of the pre-drilled hole. Therefore the positioning may be completed with a fine positioning wherein the insertion unit 17 is moved accurately to the collar of the pre-drilled hole. In the fine positioning a computer vi- sion system can be utilized or different hole identifiers can be detected, for example. The fine positioning principles are discussed above in this application and also in connection with Figure 5.

In Figure 4 an alternative arrangement is disclosed. The mining vehicle 1 is provided with one or more drilling booms 5a with drilling units 6 and one or more post-drilling or insertion booms 5b with post-drilling units or insertion units 16. In this embodiment the mining vehicle 1 is a multi-use apparatus that can be positioned and navigated to the working site in a manner disclosed in the description of Figure 3. The drilling and insertion are carried out with different booms 5a, 5b wherefore positioning data of the drilled holes are stored and utilized when rough positioning the insertion unit 17 after drilling close to the pre-drilled hole 7 indicated as a black circle in Figure 4. Positioning infor- mation can be stored in the control unit 12 of the mining vehicle 1 and, if needed, it can be communicated to one or more external control unit 13.

In Figure 5 one possible insertion unit 17 is shown. The insertion unit 17 comprises a feed beam 23 and a feed device 24 supported on the feed beam. The feed beam 23 can be attached to a post-drilling boom 5b by means of a cradle 25 or corresponding means. An insertion object 26 can be supported to a shank 27 of the feed device 24 and can be supported by a front support 28 to a front end 23a of the feed beam. Thereby the insertion object 26 is in a feed line 29 and can be pushed forward and pulled rearward by the feed device 24, which is movable on the feed beam 23. The front end portion 23a of the feed beam may comprise one or more cameras 30 in order to detect the pre-drilled holes after the insertion unit 17 is rough positioned 31 at a proximity 32 to the pre-drilled hole on the basis of collected drilling position information. Thereafter the insertion unit 17 is fine positioned 33 from the proximity position 32 accurately to a mouth of the pre-drilled hole 7. In fine positioning 33 several cameras can be used in order to produce stereo pictures or videos. The control unit 12 comprises an image processing system for detecting optically the accurate position of the pre-drilled hole 7. Alternatively or in addition to cameras the insertion unit 17 may comprise one or more identifiers, receivers or other de- tection means for hole recognition.

As can be seen in Figure 5, there may be an angle between the feed line 29 and a center line 34 of the pre-drilled hole. In case the insertion object 26 has incorrect feed direction relative to hole direction there exist forces resisting the feeding. The inserting device 17 may comprise one or more sensors, measuring units or other sensing means 35 for detecting the feed resistance. When feed resistance is detected the control unit 12 can start various feed aid measures in order to facilitate the insertion. The insertion unit 17 may comprise one or more angle adjusting device 36 by means of which a rear end portion 23b of the feed beam can be moved in transverse direction. The angle adjusting device 36 may rotate R the rear part 23b of the feed beam as it is shown in Figure 5. The rotation R is executed simultaneously with the feed F whereby a rear end of the insertion object 26 proceeds in a helical pattern. The front end of the feed beam may be supported against a rock surface or is kept stationary in some other way.

Figure 6a shows in a simplified manner start of the insertion cycle.

At the beginning the rotation R has a greater magnitude i.e rotation is per- formed with a greater radius. That is because at first the purpose is to sense and find the direction 34 of the pre-drilled hole 7. As the insertion proceeds and the insertion object 26 penetrates into the hole 7 the angle adjustment is decreased, as it is shown in Figures 6b and 6c. Further, in Figure 6c resisting forces are detected because there is an irregular portion 37 in the hole that causes problems for the insertion. Increased feed resistance is detected and the control unit may thereafter control the feeding with different feed aid control modes. According to one control mode feed direction is changed 38 between normal direction and reverse direction according to the feed resistance. In an- other control mode the insertion object 26 is rotated or turned around its longitudinal axis 39 during the feed.

In Figure 7 there is a rock surface area wherein drill holes are drilled and some of the openings of the pre-drilled holes 7 are provided with positioning aids. The pre-drilled holes 7 show as dark circles in optical detection means. A physical identifier 46 may be arranged in a drilling cycle inside the hole 7. The identifier 46 may a tubular piece having an outer edge 47 having a color or shape which improves optical detection. One possibility is to paint around the hole opening an annular identification marking 48 which improves the optical hole recognition. Furthermore, the hole may be provided with a RFID tag or corresponding machine readable active or passive wireless identifier 49.

In Figure 8 some of the above discussed embodiments and features are shown in a simplified diagram.

In some cases, the features disclosed in the present application may be used as such, irrespective of other features. On the other hand, when necessary, the features disclosed in the present application may be combined so as to provide different new combinations.

The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.

Claims

1 . A method for post-drilling insertion, the method comprising:

positioning a drilling unit (6) in a drilling boom (5a) to a starting position and directional angle of a hole (7) to be drilled;

drilling the drill hole (7) by means of the drilling unit (6);

storing position data of the drill hole (7) to at least one control unit

(12, 13);

positioning a post-drilling unit (17) in a post drilling boom (5b) to the pre-drilled hole (7);

and inserting at least one insertion object (26) into the pre-drilled hole (7) by means of the post-drilling unit (17);

c h a r a c t e r i z e d b y

implementing in the positioning of the post-drilling unit (17) two consecutive positioning steps having differing control principles;

rough positioning the post-drilling unit (17) at a proximity of a collar of the pre-drilled hole (7) according to the position data stored in the control unit (12, 13);

determining after the rough positioning the position of the collar of the pre-drilled hole (7) relative to the post-drilling unit (17) by means of at least one sensing unit (30) arranged in the post-drilling unit (17) and producing sensing data;

and fine positioning the post-drilling unit (17) to the collar of the pre- drilled hole (7) according the sensing data.

2. A method as claimed in claim 1 , c h a r a c t e r i z e d b y determining during the drilling phase the position data of the drill hole (7) by position sensing means (1 1 ) and storing the position data to at least one control unit (12, 13).

3. A method as claimed in claim 1 or 2, c h a r a c t e r i z e d b y applying in the fine positioning an optical hole recognition system, wherein the post-drilling unit (17) is provided with at least one camera (30);

and detecting the collar of the pre-drilled hole (7) by an image detection system.

4. A method as claimed in any of the preceding claims, characterized by

providing at least one pre-drilled hole (7) with at least one identifier (46, 48, 49) in the drilling phase;

detecting the identifier (46, 48, 49) by at least one detector (30) arranged in the post-drilling unit (17);

and implementing the detection of the identifier (46, 48, 49) in the positioning of the post-drilling unit (17).

5. A method as claimed in any of the preceding claims, characterized by

changing the feeding angle of the insertion object (26) during the insertion in order to find the directional angle of the pre-drilled hole (7).

6. A method as claimed in any of the preceding claims, characterized by

executing the post-drilling phase automatically in the control of the control unit of the mining vehicle.

7. A mining vehicle, comprising:

a movable carrier (4);

at least one post-drilling boom (5b) movable relative to the carrier

(4);

the post-drilling boom (5b) is provided with a post-drilling unit (17) for feeding at least one insertion object (26) into a pre-drilled hole (7);

position sensing means (11) for detecting the position of the boom

(5b);

at least one control unit (12, 13) for controlling the operation of the boom (5b) and receiving position data from the sensing means (11);

and at least one data element in the control unit (12, 13) including hole position data;

characterized in that

the control unit (12, 13) comprises a control strategy for controlling the positioning of the post-drilling unit (17) according to consecutive rough po- sitioning and fine positioning, and wherein the rough positioning is based on the data element including position data; the post-drilling unit (17) comprises at least one sensing unit (30) for producing position data of the collar of the pre-drilled hole (7);

and wherein the control unit (12, 13) is arranged to fine position the post-drilling unit (17) according to the sensed position data.

8. A mining vehicle as claimed in claim 7, characterized in that

the mining vehicle is a post-drilling vehicle (16) without any drilling unit (6).

9. A mining vehicle as claimed in claim 7, characterized in that

the mining vehicle (1) is provided with at least two booms; and a first boom is a drilling boom (5a) provided with a drilling unit (6) and a second boom is a post-drilling boom (5b) provided with a post-drilling unit (17).

10. A mining vehicle as claimed in any of the preceding claims 7 - 9, characterized in that

the data element in the control unit includes position data sensed and stored during drilling of the drill hole.

11. A mining vehicle as claimed in any of the preceding claims 7 - 9, characterized in that

the data element in the control unit includes position data defined in a drilling plan.