AU2013222034B2 - Rock drilling rig and method of positioning rock drilling unit - Google Patents

Abstract

Abstract The invention relates to a rock drilling rig and a method of positioning a rock drilling unit. The rock drilling rig (5) is provided with a detection device (4) for detecting a reference line (RL), such as a previously drilled dril[ hole fan (1). The detection device is positioned in the direction of gravity (G). The position and direction of the detected reference line are utilized when positioning a drill ing unit to a new drilling position at a predetermined horizontal reference dis tance (RD) from the reference line. (Figure 3) FIG. 1 FIG. 2 4-2a 3a 3, 5 7b

Description

1 Rock drilling rig and method of positioning rock drilling unit Background of the invention The invention relates to a rock drilling rig, and particularly to an ar rangement of determining a position of the rock drilling rig at a work site and 5 positioning a rock drilling unit. The field of the invention is defined more specifically in the pream bles of the independent claims. In mines and at other worksites, rock drilling rigs are used. A rock drilling rig is provided with a boom and a rock drilling unit attached to the boom 10 for drilling drill holes into rock surface. The rock drilling rig is positioned in drill ing positions where the drilling is executed according to a drilling plan Drill hole fans including several drill holes in a fan shaped pattern may be drilled when there is a need to reinforce tunnel ceilings and walls and when forming blasting holes for production needs. The worksite may comprise several planned drill is hole fans at a distance from each other. Positioning the rock drilling rig to a new drilling position requires complex measuring and positioning systems, which is a disadvantage. Brief description of the invention An object of the invention is to provide a novel and improved rock 20 drilling rig and a method of positioning a rock drilling unit, The rock drilling rig according to the invention is characterized in that the detection device is aligned in the direction of gravity for detecting a position of at least one reference line at a worksite of the rock drilling rig. The method according to the invention is characterized by aligning 25 the detection device in the direction of gravity and producing a detection pattern in the detection device; positioning the rock drilling rig to a new position where the detection pattern is aimed in the direction of the reference line; determining a current direction and horizontal distance of the rock drilling unit relative to the reference line; and positioning the rock drilling unit to the new drill hole line to 30 be drilled according to an input horizontal reference distance and the detected direction of the reference line, An idea of the disclosed solution is that when positioning a rock drill ing rig at a worksite for drilling a drilling pattern, a detection device arranged in the rock drilling rig is used, The detection device is aligned in the direction of 2 gravity at least during the positioning procedure. The worksite is provided with a reference line and the positioning to a new drilling position is executed accord ing to the reference line, which is detected by means of the detection device. After the reference line is detected, the current direction and horizontal distance 5 of a rock drilling unit relative to the reference line is determined. This step is called navigation. The drilling unit of the rock drilling rig is positioned to the new drill hole line to be drilled according to an input horizontal reference distance and the detected direction of the reference line, Owner of the mine may define the reference distance between successive drill hole fans or other drilling pat 10 terns. This type of drilling process may be called reference drilling. An advantage of the disclosed solution is that the positioning does not require complicated measuring devices and calculations for determining the position and direction of the reference line. No measuring means external to the rock drilling rig are required. Since the detection device is in the direction of 15 gravity, there is no need to measure the vertical distance and inclination be tween the reference line and the detection device. This simplifies the detection and navigation process. An additional advantage is that the work of an operator becomes easier and less demanding. According to an embodiment, the reference line is formed of realized 20 driH holes, i.e. the reference line passes through the pre-drilled drill holes. An advantage of this solution is that there is no need to make any reference mark ings to a worksite in a separate step, which allows extra marking work to be avoided and may speed up the process. According to an embodiment, the reference line is formed of at least 25 two realized drill holes. The realized holes produce a vertical reference plane, which is detected by the detection device that is in the direction of the gravity. According to an embodiment, a previous realized drill hole fan serves as a reference line for the next drill hole fan to be drilled. The fan may be a rein forcing or bolting fan that comprises several drill holes positioned upwards and 30 on the sides in a tunnel or corresponding rock cavern. Alternatively, the fan may be a blasting hole fan comprising drill holes pointing perpendicularly upwards and drill holes pointing angularly upwards. According to an embodiment, the reference line is formed of refer ence markings made to the worksite, i.e. the reference line passes through the 35 reference markings. The reference markings may be markings that have been 3 painted on rock surfaces. Alternatively, the reference markings may be elec tronic devices such as transmitters, RFID -tags or beacons. Further, the refer ence markings may be devices comprising a reflector or a eight source, By means of the reference markings a first reference position can be determined or 5 reference markings can be done in critical positions of the mine, for example. According to an embodiment, the detection device produces a fan shaped detection pattern, the fan-shaped detection pattern pointing upwards and sidewards relative to the rock drilling rig. The detection pattern may have a shape of a circle. Alternatively, the detection pattern may have a shape of a 1o sector of a circle. In some situations it may be sufficient that an angle of the sector is 90' and that only one sector is produced. According to an embodiment, the fan-shaped detection pattern is a turning beam pattern. The beam pattern can be generated by means of a rotat ing or tuning emitter sending a detection beam in a vertical plane. Because the 15 beam is turning or rotating, it is sufficient that only one beam is emitted. How ever, it is possible to use several beams too. According to an embodiment, the fan-shaped detection pattern is formed of at least two narrow beams having the shape of a fan, Two beam emitters are arranged in an angular position relative to each other, and together 20 they produce one uniform fan-shaped pattern that extends upwards and side wards. Interference of the two fan-shaped beams can be prevented by means of one or more blanking plates. According to an embodiment, the fan-shaped detection pattern corn prises at least three beams, One beam may be directed upwards and two or 25 more beams may be directed sidewards, or obliquely upwards, whereby they are at an angle relative to the beam pointing upwards. The beams may be nar row and point-like so as to produce illuminated points on a rock surface. According to an embodiment, the detection device is a laser emitting device, The laser emitting device may comprise one single laser beam ar 30 ranged to be turned or rotated, or two, three or more laser beams may be ar ranged to form a fan shaped pattern, as discussed above. Further, the beam of the laser may have a form of a narrow fan producing an illuminated line on a rock surface, or the beam may be narrow and point-like so that it produces a small illuminated point on a rock surface.

4 According to an embodiment, the detection device is a camera, By means of one or more cameras, pre-drilled holes, reinforcing bolts and refer ence markings can be detected, The camera may be a video camera or a still camera. Image data produced by the camera can be processed in an image 5 processor in order to detect positions of pre-drilled holes, reinforcing bolts and reference markings on the observed rock surface. The image processor may include an image recognition system. At its simplest, the image data may be shown on a display unit for an operator, whereby the operator may use the dis play image as a sighting tool. 10 According to an embodiment, the detection device is an ultrasound emitting device. By using ultrasonic waves it is possible to detect drilled holes in the rock surface, reinforcing bolts or artificial physical reference markings. The ultrasound emitting device can detect such physical discontinuities on the rock surface. Thus, the ultrasonic means can be also used for determining the posi 15 tion of the reference line. According to an embodiment, the detection device is located at a predetermined horizontal distance from the rock drilling unit., The predetermined distance is set according to a drilling plan and corresponds to a designed hori zontal distance between successive drill hole fans to be drilled. The distance 20 between the successive fans, ie. the reference distance can be defined by the owner of the mine, Alternatively, the detection device may be located at a pre determined horizontal distance from a zero point of a coordinate system of the rock drilling rig. A control unit may execute needed calculations for determining the positions. 25 According to an embodiment, the position of the detection device is arranged to be adjustable in a horizontal direction relative to the drilling unit. This embodiment allows the position of the detection device to be adjusted in case the reference distance changes significantly. The detection device may comprise position adjusting means that include a slide and bars for supporting 30 the slide, for example. According to an embodiment, the detection device is arranged to the boom, It is easy and fast to move the detection device to a correct position and direction so that the detection pattern in accordance with the reference line is obtained. In this embodiment there is no need to direct the carrier of the rock Cf2U 1 4teb TsYO.LU 4A 5 drilling rig according to the direction of the reference line, which speeds up the positioning drive of the carrier. According to an embodiment, the detection device is arranged in the carrier. This embodiment may be useful when the reference distance is long. 5 Further, the carrier may be provided with free space for the detection device and the detection device can be easily positioned to a secure place. According to an embodiment, the detection device is aligned in the direction of gravity only when the position of the reference line is determined. Rest of the time the detecting device may be positioned in a transport position 10 under a protective cover, for example. According to an embodiment, the detection device is continuously aligned in the direction of gravity. According to an embodiment, the detection device produces or re ceives detection signals only when the position of the reference line is deter 15 mined. Rest of the time the detection device may be switched off. According to an embodiment, the detection device produces or re ceives detection signals continuously. According to an embodiment, the detection device comprises a pen dulum, which is arranged to turn about a horizontal turning axis. The detection 20 device is provided with at least one detection unit, which is arranged to the pendulum. The pendulum tries to keep its position in the direction of gravity since the center of mass of the pendulum is arranged to be below the turning axis. According to an embodiment, the detection device comprises a pen 25 dulum, which is arranged to turn about a horizontal turning axis and aims to keep its position in the direction of gravity. The turning motion of the pendulum is dampened by means of one or more damping devices, Because of the damp ing means the movement of the pendulum and the detection unit arranged in the pendulum can be more stable, 30 According to an embodiment, the damping device comprises a basin, damping fluid in the basin, and one or more damping surfaces immersed in the damping fluid. The basin is located under the pendulum and the damping sur face is arranged to move together with the pendulum. The damping fluid may be oil, for example. When the pendulum turns relative to the turning axis the 3s damping surface moves inside the basin. The damping fluid in the basin has 40mwij 3||1PMMW 6 viscosity whereby the fluid dampens the movement of the damping surface and the pendulum. Such a damping device is simple, inexpensive and reliable. According to an embodiment, the detection device comprises one or more sensors or measuring means for determining the current direction of the 5 detecting device and detecting the direction of the gravity. Further, the detecting device comprises one or more turning devices for positioning the detecting de vice in the direction of gravity on the basis of received measuring data. The di rection of the detection device may be controlled either continuously or only when the reference line needs to be detected. The detection device may be 10 provided with a control device for the position control In this embodiment the direction of the detection device is actively controlled. According to an embodiment, the detection device comprises at least one transparent cover arranged on the upper side of the detection device. The shielding cover provides overhead protection for the detection device against 15 dropping stone material moisture and impurities. The cover improves durability and reliability of the device, According to an embodiment, the detection device comprises at least one overhead cover and at least one cleaning device for keeping the cover free of impurities, The cleaning device may comprise one or more flushing nozzles 20 whereby the cover may be cleaned by means of water jets, for example. Alter natively or in addition, the cleaning device may comprise one or more wiper blades or corresponding mechanical cleaning means. According to an embodiment, a position of the rock driling unit rela tive to the detection device is determined. The boom is provided with boom 25 measuring means for measuring positions of boom parts, and the carriage is provided with inclination measuring means for measuring an inclination of the carrier. The control unit determines the position of the rock drilling unit relative to the detection device on the basis of measuring data received from the meas uring means. The driling unit is then navigated relative to the detected refer 30 ence line on the basis of the measuring data and known location of the detec tion device in the rock drilling rig. According to an embodiment, the rock drilling rig is provided with at least one display unit, and the control unit is configured to display on the display unit a current horizontal position of the rock drilling unit relative to the detected "Mltfl~& OAMii POO4ALS VMMt 7 reference line. This feature facilitates positioning the drilling unit to a predeter mined horizontal distance from the reference line. According to an embodiment, the rock drilling rig is provided with at least one display unit, When the drilling unit is positioned to a new drilling loca 5 tion at a reference distance from the reference line, the control unit is able to display on the display unit the current position of the rock drilling unit relative to start points of the holes to be drilled. Typically the distance between the start points is predetermined by a mine owner. This feature facilitates and speeds up the positioning of the drilling unit at the defined locations in a drilling fan or other 10 type of drilling pattern. According to an embodiment, the control unit is arranged to instruct the operator positioning the drilling unit at a predetermined horizontal distance from the reference line. Further, the control unit may instruct the operator posi tioning the drilling unit at suitable start points in a drill fan. The distance to a is start point of a hole to be drilled next can be indicated to the operator, for in stance. Instructions, such as measuring data and various sighting patterns can be shown on a display unit, for example. According to an embodiment, the positioning process comprises a rough-positioning, wherein the carrier is moved so that the detection pattern of 20 the detection device is at the reference line. Thereafter a fine-positioning may be executed so that the detection pattern is arranged in the direction of the ref erence line. When the detection device is arranged to the boom, it is relatively easy to turn the boom so that the detection pattern coincides with the reference line. Also the horizontal position may be fine adjusted, When the detection pat 25 tern is according to the reference line, navigation is executed. In the navigation, positions of boom parts of the boom are measured by means of boom measur ing means, and inclination of the carrier is measured by means of inclination measuring means. Navigation further comprises calculating in a control unit of the rock drilling rig the position of the rock drilling unit relative to the reference 30 line on the basis of measuring data received from the measuring means and the predetermined position of the detecting device attached to the boom. The determined current position of the rock drilling unit in relation to the reference line can be indicated on a display unit to an operator, According to an embodiment, the disclosed detection device and the 35 disclosed positioning process may be utilized also when there is a need to fin- 8 ish a drill hole pattern, such as a fan that is partly drilled and includes pre-drilled holes and undrilled holes. The position of the last pre-drilled hole in an unfin ished drill hole line is assigned by positioning the drilling unit to the last realized drill hole in the unfinished drill hole line. Thereafter navigation is executed and 5 the control system may instruct the operator to drill the next drill hole to be drilled in the unfinished drill hole line. Alternatively, the control unit may take care of the drilling of the unfinished drill holes automatically. According to an embodiment, the rock drilling rig is positioned to a new drilling position so that the drilling unit may be utilized for drilling two or 10 more successive drill hole fans or other patterns at a horizontal reference dis tance from another. This may reduce the need for positioning drive of the carri er. In this embodiment the horizontal reference distance has to be relatively short According to an embodiment, the rock drilling rig is a bolting device Is provided with a bolting unit that comprises a drilling unit for drilling drill holes in a fan-shaped pattern. Further, the bolting device comprises a bolting unit for arranging reinforcing bolts into the drilled holes, According to an embodiment, the rock drilling rig is a production drill ing rig that is designed for drilling blasting holes into the rock. Such a device is 20 provided with a drilling unit for drilling drill holes upwards according to a blast ing-technical pattern. Above disclosed embodiments may be combined in order to form suitable solutions having those of the above features that are needed. Brief description of the figures 25 Some embodiments are described in more detail in the accompany ing drawings, in which Figure 1 shows schematically a perspective view of a tunnel having successive drill hole fans, Figure 2 shows schematically a tunne having two realized drill holes 30 forming a reference line when detected by detection patterns directed in the direction of gravity, Figure 3 is a schematic side view showing a rock drilling rig for drill ing drill hole fans at a reference distance from each other, Figure 4 is a schematic top view illustrating a rock drilling rig posi 35 tioned at a previous drilled fan serving as a reference line, 9 Figure 5 is a schematic top view showing a detection device ar ranged to a boom so that a carrier may be at an angle relative to a detected reference line, Figure 6a shows schematically a rock drilling rig from a side and the Stop when a carrier is rough-positioned by driving near the reference line, and Figure 6b shows the situation after the carrier has been lifted on support legs and fine-positioning is executed by moving a boom, Figure 7 shows schematically a detection device and two narrow fan shaped detection patterns produced, 10 Figure 8 is a schematic sectional view of a detection device, wherein emitters are arranged in a pendulum and movement of the pendulum is damp ened, and Figure 9 is a schematic top view illustrating positioning of a drilling unit to an unfinished drilling pattern, 15 For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements. Detailed description of some embodiments Figure 1 shows two successive drill hole fans 1 drilled at a predeter 20 mined horizontal reference distance RD from each other. The reference dis tance RD is normally defined by an owner of a mine, The drill hole fans 1 com prise several drill holes 2, which may be located on walls and a ceiling of a rock cavern. The direction of the drill holes 2 is crosswise to a tunnel line. Blasting a round may damage the rock defining the tunnel contour, 25 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 and walls of the tunnel. The rock may be reinforced by drilling several adjacent reinforcement holes to which a rock bolt or similar reinforcement members may be fitted. Alternatively drilling may be executed for generating blasting holes 30 when rock is excavated for production purposes, The blasting holes can be drilled in a fan-shape too. Figure 2 shows in a simplified manner that at least two realized drill holes 2 or artificial reference markings are needed in order to determine a ref erence line and a vertical reference plane. The realized drill holes are detected 35 by detection patterns 3 produced by a detection device 4. The detection device 10 4 is arranged to be in the direction of gravity G at least during the detection pro cess. The detected realized drill holes 2 and the direction of gravity G deter mine the reference line, which is used for determining the position of a drilling unit of the rock drilling rig at a new driving location at a distance from the refer 5 ence line. Figure 3 shows a rock drilling rig 5 positioned into a tunnel or a simi lar rock cavern The rock drilling rig 5 comprises a movable carrier 6 provided with at least one drilling boom 7 which has a rock driling unit 8 at its outermost end. The drilling unit 8 comprises a feed beam and a rock drilling machine sup 10 ported by the feed beam. The boom 7 may comprise several boom parts 7a, 7b. The boom 7 comprises several joints 9 and the length of the boom can be changed. The boom 7 is provided with measuring means 10 such as sensors or measuring devices. Any other measuring principle and device may be used to determine the positions of the boom 7. Furthermore, inclination of the carrier 6 15 can be detected by an inclination measuring device 11, such as an inclinome ter. The position and direction of the drilling unit 8 can be determined in one or more control units 12 on the basis of measuring data received from the boom measuring means 10 and the inclination measuring device 11. The control unit 12 may display the positioning data and other information for an operator 13 on 20 a display device 14., As shown in Figure 3, successive drill hole fans 1 are drilled and, be tween the fans, a horizontal reference distance RD is utilized. In the Figure a previous realized fan is detected by a detection device 4 situated on the boom 7. A detection pattern or beam coincides with drill holes 4 of the previous fan 1, 25 the rock drilling rig being navigated on the basis of this information. Alternative ly, the detection device 4a may be situated on the carrier 6. The detection de vice 4 may be construed so that the detection pattern is automatically aimed upwards in the direction of gravity. Alternatively, the direction of the detection device 4a may be controlled actively, which requires position measuring and a 30 suitable actuator for moving the detection device in the direction of gravity. Drill holes 2 may be drilled in the direction of gravity or they may be directed at a desired angle relative to gravity. The latter situation is shown by a broken line 2a.

11 Further, it is possible to make reference markings 15 on a rock sur face and to use them when determining the reference line. Such reference markings 15 may be used for defining a first reference position, for example. In Figures 4 and 5 a detection device 4 is positioned so that a detec 5 tion pattern is at a reference line RL defined by starting points of drill holes of a previous drill hole fan, Figure 5 illustrates that the direction of a carrier 6 may deviate from the direction of the reference line RL since the detection device 4 is attached to a boom 7. The detection patten can be directed simply by turning the boom 7 and the moving boom parts. 0 In Figure 6a a rig 5 is rough-positioned near a reference line by mov ing a carder 6, As can be noted, a detection pattern 3 and a reference line RL do not coincide, wherefore a more accurate positioning is needed, In Figure Bb the carder 6 has been ifted on support legs 8 and the carrier is no longer moved, thus fine-positioning is executed by moving the boom 7 only. 15 In Figure 7 a detection device 4 produces two narrow fan-shaped de tection patterns 3. Such a fan-shaped detection pattern forms an illuminated line when it hits a rock surface. It is easy to compare the directions of the pro duced detection line and a line of realized drill holes or a line of reference mark ings. 20 Figure 8 shows a detection device 4 in which emitters or detection units 16 are arranged in a pendulum 17 and movement of the pendulum 17 is dampened by a damping device 18. The pendulum 17 is arranged to turn about a horizontal turning axis 19. The pendulum 17 tries to keep its position in the direction of gravity since the center of mass of the pendulum is arranged to be 25 below the turning axis 19, The turning motion of the pendulum 17 may be dampened by means of the damping device IS, which may comprises a basin 20, damping oil 21 in the basin 20, and damping surfaces 22 immersed in the damping oil 21. The basin 20 is located under the pendulum 17 and when the pendulum 17 tums relative to the turning axis 19 the damping surfaces 22 move 30 inside the basin 20. The damping oil 21 dampens the movement of the damping surfaces 22 and the pendulum 17, Further, the detection device may comprise a transparent cover 23 arranged on the upper side of the detecting device 4. The cover 23 may be kept clean by means of a cleaning device 24, which may comprise a flushing nozzle, 35 for example, Further, it may be possible to arrange several transparent protect- 12 ing films on the cover 23. Then, instead of washing the cover 23, the protecting films may simply be removed one by one when dirt accumulates on the cover, It is also possible to arrange blanking plates P to prevent interfer ence between the detection patterns produced by the detection units 16, s Figure 9 illustrates positioning of a drilling unit 8 to an unfinished drill ing fan 1a, The above-disclosed detection and positioning processes may be utilized also in this case. Such an unfinished fan 1a includes pre-drilled holes 2 and undriled holes 2c. At first the position and direction of a previous fan I are detected. On the basis of the reference distance RD and a determined refer 10 ence line RL, the position and direction of the unfinished fan Ia are determined. In a second phase, the position of a last predrilled hole 2b in the unfinished drill hole fan 1a is assigned by positioning the drilling unit 8 to the last realized hole 2b. Thereafter navigation is executed and the drilling unit 8 can be positioned at a start point of the next undrilled drill hole 2d. 15 The drawings and the related description are only intended to illus trate the idea of the invention. In its details, the invention may vary within the scope of the claims. In the claims which follow and in the preceding description of the in vention, except where the context requires otherwise due to express language 20 or necessary implication, the word "comprise" or variations such as t"comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to 25 herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims (14)

1. A rock drilling rig for drilling holes on a ceiling and walls of a tun nel, comprising: 5 a movable carrier; at least one boom; at least one rock drilling unit arranged at a distal portion of the boom; at least one detection device; and at least one control unit; 10 w h e r e i n the detection device is aligned in the direction of gravity for detecting a position of a reference line which is formed of at least two-predrilled drill holes on the ceiling and walls of the tunnel. 15

2. The rock drilling rig as claimed in claim 1, w h e r e i n the detection device has a detection pattern which is fan shaped and points upwards and sidewards relative to the rock drilling rig.

3. The rock drilling rig as claimed in claim 1 or 2, w h e r e i n 20 the detection device is a laser emitting device.

4. The rock drilling rig as claimed in any one of the preceding claims, wherein the detection device is attached to the boom. 25

5. The rock drilling rig as claimed in any one of the preceding claims, w h e r e i n the detection device is located at a predetermined horizontal dis tance from the rock drilling unit; and 30 the predetermined distance is set according to a drilling plan and cor responds to a designed horizontal distance between successive drill hole fans to be drilled. 6604244_1 (GHMatters) P94708.AU DENISET 15

6. The rock drilling rig as claimed in any one of the preceding claims, wherein the detection device comprises a pendulum arranged to turn about a horizontal turning axis; 5 the detection device is provided with at least one detection unit ar ranged to the pendulum; and center of mass of the pendulum is below the turning axis, the pendu lum thus setting in the direction of gravity. 10

7. The rock drilling rig as claimed in claim 6, w h e r e i n the detection device comprises at least one dampening device for damping the turning motion of the pendulum.

8. The rock drilling rig as claimed in any one of the preceding claims, 15 w h e r e i n the detection device comprises at least one transparent cover ar ranged on the upper side of the detection device for overhead protection.

9. The rock drilling rig as claimed in any one of the preceding claims, 20 w h e r e i n the boom is provided with boom measuring means for measuring positions of boom parts of the boom; the carrier is provided with inclination measuring means for measur ing an inclination of the carrier; and 25 the control unit is configured to determine the position of the rock drilling unit relative to the detection device on the basis of measuring data re ceived from the measuring means.

10. The rock drilling rig as claimed in claim 9, w h e r e i n 30 the rock drilling rig is provided with at least one display unit; and the control unit is configured to display on the display unit the current position of the rock drilling unit relative to the reference line. 6604244_1 (GHMatters) P94708.AU DENISET 16

11. The rock drilling rig as claimed in any one of the preceding claims, w h e r e in the rock drilling rig is a bolting device provided with a bolting unit; and 5 the bolting unit comprises a drilling unit for drilling drill holes in a fan shaped pattern.

12. Method of positioning a rock drilling rig for drilling drill holes on a ceiling and walls of a tunnel, the method comprising: 10 detecting a reference line which is formed of at least two pre-drilled drill holes on the ceiling and walls of the tunnel, by means of at least one detec tion device arranged on the rock drilling rig; and positioning a drilling unit of the rock drilling rig to a new drill hole line according to the detected reference line; 15 w h e r e i n aligning the detection device in the direction of gravity and producing a detection pattern by the detection device; positioning the rock drilling rig to a new position where the detection pattern is aimed in the direction of the reference line; 20 determining a current direction and horizontal distance of the rock drilling unit relative to the reference line; and positioning the rock drilling unit to the new drill hole line to be drilled according to an input horizontal reference distance and the detected direction of the reference line. 25

13. The method as claimed in claim 12, wherein using in the positioning process a detection device arranged to a predetermined position of the boom of the rock drilling rig; moving a carrier of the rock drilling rig to a new drilling position for 30 drilling at least one fan-shaped drill hole line; rough-positioning the carrier in the new drilling position so that the detection pattern of the detection device is at the reference line; fine-positioning the detection pattern in the direction of the reference line by moving the boom; 6604244_1 (GHMatters) P94708.AU DENISET 17 measuring positions of boom parts of the boom by means of boom measuring means, and measuring an inclination of the carrier by means of in clination measuring means; calculating in a control unit of the rock drilling rig the position of the 5 rock drilling unit relative to the reference line on the basis of measuring data received from the measuring means and the predetermined position of the de tection device in the boom ; and indicating in at least one display unit the determined current position of the rock drilling unit in relation to the reference line. 10

14. The method as claimed in claim 12 or 13, w h e r e i n positioning the rock drilling unit to an unfinished drill hole line having at least one predrilled drill hole and at least one undrilled hole, the unfinished drill hole line being at the reference distance and direction relative to the de 15 tected reference line; positioning the drilling unit at a pre-drilled hole in the unfinished drill hole line for assigning the last pre-drilled hole; positioning the drilling unit in the unfinished drill hole line to a start position of an undrilled hole being at a predetermined distance from the detect 20 ed last pre-drilled hole; and finishing off the drilling by drilling several unfinished drill holes. 6604244_1 (GHMatters) P94708.AU DENISET