METHOD OF POSITIONING A FEED BEAM PROVIDED WITH A ROCK DRILLING MACHINE

METHODE DE POSITIONNEMENT DE POUTRES D'ALIMENTATION AU MOYEN D'UNE MACHINE A PERCER LE ROC

English Abstract

A method of positioning a feed beam provided with arock drilling machine.
Two at a distance from each other on the feed beam (12) positioned
ultrasonic transmitters (16,17) together with three microphones (13,14,15),
which have been positioned in laser beams (33,34,35), are used for measuring
the positions in space of the transmitters. The feed beam is then positioned
such that the transmitters obtain those coordinates in a rock fixed
coordinate system Which give desired position and direction for the feed
beam.

Claims

4
Claim:
A method of positioning a feed beam (12) provided with a rock drilling
machine (11) in a predetermined position and with a predetermined direction
relative to a common coordinate system for a rock body (21), characterized
in that at least three electromagnetic beams (33,34,35) are created with
predetermined direction and position in a room (22), that a
receiver/transmitter (13,14,15) for oscillation energy is positioned in each
of said electromagnetic beams, that at least two transmitters/receivers
(16,17) for oscillation energy are positioned at a distance from each other
on said feed beam (12), that the delay time interval for oscillation energy
between each of said transmitters/receivers on the feed beam and each of
said receivers/transmitters positioned by means of said electromagnetic
beams is measured and that the positioning of the feed beam is controlled
such that said measured delay time intervals achieve predetermined values.

Description

~ '
13329~8
A method of positioning a feed beam provided with a rock drilling ~ch~ne
The present invention relates to a method of positioning a feed beam
provided with a rock drilling ~^hlnP in a predetermined position and with a
predetermined direction relative to a coordinate system common for a rock
body. The method according to the invention is particularly suitable for use
in so-called production drilling, i.e. when mineral, whose position in space
earlier has been determined by means of prospecting drilling or other
methods, is to be mined.
According to prior art one has, in order to achieve high precision in the
positioning of the rock drilling -chln~, had to use complicated measuring
methods performed by special mine surveyors. Because of this one has had to
decrease the d~ - ds for accuracy in the measurement in order not to make
the mining too expensive and slow. As a consequence one has obtained more
rock waste in the mining which has increased the costs. Therfore, one had to
balance between the requirements of low measuring costs and little rock
waste.
Through the present invention, which is defined in the subsequent claims, a
simple and accurate measuring method is achieved. In the method according to
the invention oscillation energy is used in order to measure the distances
between a number of points which are fixed, although movable relative to the
coordinate system made up for the area where drilling is to occur, and some
points which are fixed relative to the drilling -^hln~. This oscillation
energy can for instance be in the form of ultrasonic, microwave or optical
radiation. The ultrasonic technique has the advantage of being both cheap
and accurate. One can increase the accuracy through increasing the frequency
of the ultrasonic signal. The frequency is mainly limited by the damping of
the signal which results therein that the measurable distance becomes
impractically short at too high frequencies. A frequency of 100-200 kHz has
turned out to be suitable.
The fixed receivers/transmitters, the mic,ophones, are positioned by means
of elec~ qEr~tic beams, for instance laser beams, which are sent out in
predetermined, preferably parallel, directions. The beams have predetermined
positions in space. In order to get the microphones in a certain plane a
87010utlans

2 1 3 3 2 9 ~ 8
turnable microprism is used which is positioned in one of the laser beams.
With this set-up one can continue with the drilling for 10-15 m before a new
set-up of the microphones is needed. The positioning of the microphones
lengthwise in the tunnel is determined by means of a measuring tape. Those
transmitters/receivers which are positioned on the feed beam of the drill
rig are suitably ultrasonic generators.
In the practising of the invention one suitably uses a microprocessor with
accompanying memory for storing the different measured delay time intervals
and for calculating how the feed beam should be steered in order that the
predetermined position and the predetermined direction is to be achieved.
Such a system can control the presentation of the position of the feed beam
on a display or in a more automized system directly control the drill rig so
that the drilling can take place in a fully automatic way.
An embodiment of the invention is described below with reference to the
accompnying drawing which schematically shows a mine gate and a feed beam
provided with measuring equipment for the practising of the invention
positioned therein.
In the drawing a rock body 21, in which a room 22 has been blasted, is
shown. When the invention is practised three electromagnetic beams, for
instance laser beams, 33,34 35 are created in predetermined, preferably
parallel, directions with predetermined positions. A microphone 13,14 and 15
respectively is positioned in each of the elec~L. ~gnetic beams. In order to
get the microphones in a common plane a not shown turnable microprism is
used. In this way one can easily obtain a microphone plane which is parallel
to another microphone plane situated at a distance. In the room 22 a drill
rig, of which the feed beam 12 is shown, is placed. The feed beam is
provided with a rock drilling machine 11 movable to-and-fro along the feed
beam. Two ultrasonic transmitters 16,17 are provided on the feed beam.
Through measuring of the delay time interval for the ultrasonic sound
between each of the sound transmitters and each of the microphones the
positions of the ultrasonic transmitters in space is determined. Through
this the position and direction of the feed beam in space is determined. The
feed beam is then controlled, manually or automatically, so that the
ultrasonic transmitters come into predetermined positions relative to a
87010utlans

. -- ~
1~32~
7!--
common coordinate system for the rock body 21. The delay time intervals
between the transmitter 16 and the different-microphones are represented by
the Lengths of the lines 63,64 and 65. The delay time intervals between the
transmitter 17 and the different microphones are represented by the lengths
of the lines 73,74 and 75. When so is desirable the measurements and
calculations of positions and directioons and possibly automatic alignment
of the feed beam are performed with the aid of a microprocessor.
87010utlans

Representative Drawing