In a previously known method the drill pattern is calculated in a planning process separated from the rock drilling rig. After that the position of the individual drill holes are given to the driller who after that aligns the rock drilling machines for drilling. Alternatively data for the individual drill holes can be stored in a control sytem for subsequent drilling.

The present invention, which is defined in the subsequent claim, aims at automatically generating a drill pattern outgoing from rules for placement of drill holes and direction of drill holes and interactive indication of the limits for a whole round. One advantage with this method is that one does not have to handle data for the individual drill holes.

An embodiment of the invention is described below with reference to the accompanying drawing in which fig 1 shows a stylized rock drilling rig and a tunnel front on a screen. Fig 2 shows a generated drill pattern on the screen.

At generation of the drill pattern one starts from rules for placement of drill holes relative to each other within a group of holes, distance to other hole groups and different look-out angles to be used for the different hole groups. These rules are created in a planning process outside the rock drilling rig 1. These rules are loaded into the control system of the rock drilling rig 1. It can also occur that a planned volume for drilling and blasting is transferred to the rock drilling rig 1. On the screen 3 of the rock drilling rig 1 a schematised picture of the rock drilling rig 1 is shown with drill booms provided with feed beams 2 for rock drilling machines marked. On screen 3 a rock volume 4 is shown both from above and from the front. By moving the feed beams 2 the driller points out the different corners on the drill front 5 and stores these values in the memory of the control system. Through this the limits of the drill front have been pointed out and adjusted. After this the depth of the round to be drilled and blasted is given. Then it is indicated how the rear surface of the round is to be adjusted relative to the drill front. When this has been done the control system of the rock drilling rig contains information about the limits in the room of the round and the rules for the placement of the drill holes including the direction for the drilling. Outgoing from this information the drill pattern is automatically generated through automatic calculation outgoing from the stored rules and the limitations of the round. In fig 2 the completed drill pattern is shown. If the coordinate system of the rock drilling rig before generation of the drill pattern was connected to the coordinate system of the rock body the connection is kept, if not automatic connection of the coordinate systems occurs outgoing from the corners of the round pointed out.