CA2245026A1 - Multi-shot blasting system and method - Google Patents

Abstract

A method and system for causing a multi-shot blast is disclosed and claimed. According to the method, suitable positions for detonators 14.1 to 14.8 are determined in situ. Position related data (x;y) is determined automatically for each position utilizing a GPS system and also identification cods data of each detonator. This data is transferred to a controller 16 via a data-capturing device 18. The controller establishes a blast programme including inter hole delay times calculated by taking into account the position related data, geological structure, hole depth, mass of explosive in hole etc. The controller transmits signals including delay time data to the detonators, to cause them to detonat~ according to the programme.

Description

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INT~ODUC~nON A~lD BACKGRO~ND
THIS ir~vention relates to e.~plesive firing arrangemen2s ar~d more particularly to an exptos~ve firin4 system comprising a plurality of el~c~(onic detonators and a controller therefor, the CG~ ~troller, in use, causing the 5 detonators to initiate their a~soci~te~ exrlQsive charges according to a programme in a m~lti-shot bi~st.
' ', ' hring systems including a controller which is connectable by elec~rical wires to a plurality of identical detonators and wherein each detonator is 10 ~ssoci-ted with an identification code individ~al thereto, aro known. In use, the de~onators with their ~5soeiat~d charges are located in pr~planned positions and the electrical connection is made. Pre-computed delay t~me data associoted with each detonator is transmitted together with the identificauon codes on the wires to the detonators and the delay time data 1 !j assoc;ated with each detona~or is stored in a memory arrangem~nt of that detonator. Upon receipt of a common fire signal, the detonators time out the relevant delay times and then in-~iate their assori~ted charges, to cause thc multi-shot blast 20 A disadvantage of the above system is that the exact physical location of the detonators in use and the relevant delay times rnust t)e planned and worked out in ad~/ance. The aforementioned system ttlUs lacks flexibility and does no~ provide an optirnum match wi~h sophisticated blast controllers ~, ' .
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and comput~rized con~ol sy-t~ ~ which are adapted also to utilize data regarding geological structure and formations as an input for c~'~l ~ting delay times and which may thus allow for s~ ~hse~ nt chanç~es or madlfications to a delay time pro~ am, to optimize the pro~ ,ir~t~

OB~EC~ OF THE I~T INVENTION -Accordingly it is an object of the present invention to provide a method and system with which the appllcant belleves the aforementioned shortcomings may at least be alleviated SUMMARY OF THE INVENTION
According to the invention there is provided a m~hod of causing a multi-shot blast including the steps of - selecting a plurality of spaced posibons for locating electronic d-tonators in a blast site;
- a~ each position, determining position related data for that detonator position;
- utllizin~ the posieion rela~ed data to establish a blast programme - providing si~nals to detonators at the detonator positions, to - cause th-m to detonate ~ccordino to th- proy~J~ e . ~ '.

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It will be appreciated t~at ~he me~hod accor~i"~ to the ;nvent;on provides more f~exib;lity in Shat once the detonators are positioned, their p~sition data and other data, such as ~eolo~lc~l data, may be utilized to compute delay time data ~or each detonator position, to cause a desired firin~
5 sequence and hence blast front.

Further according to ths invention the method may includ~ the s~ep of determining identification'code data of each of the detonators before estat~lishing the blast programme. The identitica~-on code data may be 10 determined by reading the data electronically from a memory arrangem~nt in the detonator. However, the step of determining detonator identification code data preferably ;ncludes deterrnining the data passively. In this specification the term "determinin~ the data passively' will me~n that the data is determined witho~t electrically ener~izing the detonator. For 15 example, the data may be determined passively by readins identification code data provided on the dstonator In the ~orm of a bar code pattern, by means of a bar code reader.

The position related data may be dete~mined by absolute posib-on 20 monitoring, allernatively by distance-related monitorin~ by determ;ning distances between the detonator posiiioQs. The position related data may ~e deterrnined automaticaily u~ilizing any suitable measuring means such as a radio device, an acoustic device,''an optl'cal device, a laser operated . CA 02245026 1998-08-12 device. In a preferred forrn of the invention, absolute pasition related data is d~terrnined by dete~nining position coordinate data for ea~ h detonator pos~tion. The position coo~dinate data is preferably determined u~lizing a global posiU~ning system (GPS) includin~ a GPS receiver and at least one ~i earth orbiffng satellite.
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In the method accordirlg to the invention the position related data and iden~ficabon code data may be captuted at the detonator positions in a data reading, storing and downloadin~a device.

The captured data may then be downloade~l into a remote central controller for establishing the blast programme upon inputtin~ of the data into the controller.

15 The step of providing signals to the detonators may include the step of transmitting to each of the d~tonators, utilizing its respective identifica.ion code data as an address, delay item data relatin~ to a dclay time from a common fire signal for each detonator to datonate.

.;' 20 Further according to the invent;on and before the delay time data is ~ransmitted to the detonators, the detonators may be energized by ra.~s~ittin~ an ener~ signal to the detonators.

The detonators may be energized via electr~cal wiring extending between the controlle~ and tJ~e detonators. In an alternatJYe embodilT~nt the detonators may be energized by transmittin~ a wireless e-.er~ .g si~nal, such as a radio frequcr cy (RF) energizing sign~l to the detonators.

The delay time data may a~so be transmitted on the electrlcal wiring connecting the de~onators to the central conuoller. In the altema~ive embodi~ .t the data may be transmitted by wi~eless L~ans..~ission.

10 The common fire si~nal may also be transm;tted on the wiring, ai~ernatively in the form of a wireless signal.

Also included within the scope of the ;nvention is a method of timing a multi-shot blast including the steps of:
16 - locabng a detonator arrangement including a detonator having a preprogranl-,.ed identification code; and an associated explos;ve char~e, in each of a plurality of spaced detonator positions;
- at each position, determin;ng respective detonstor identification code data relating to the detonator at that position and respectiv- position related data for that detonator - position;

- trans~erring th~ respective deton~tor identifica~ion code data and res~ective pos;~ion related data to a c~tral contrulier;
- computing for each de~onato- position, data relating to a respective deJay time from reception of a common fire si~nal after which the det~nator at that detonator posit;on must ~ ~ cause its associated charge to explode;
- utiliang the respective detonator identification code data aru~
a--s~,-itting the respective delay time data to each detonator at said detonator positions; and - - - t-~-.5mitting a common fire signal to each detonator, tO cause its associated charge to eYpl~le after the resrec~ive delay ~ime . computed for that deton~tor position.

Yet further included w;thin the scope of the present invention is a meth~d 15 of preparing a blast sste, the me~hod including the steps of:
- seiecting a plurality of sp~ced positions for locating electronic detonators;
- at each position, determining position related data for that detonator position; and - transferring the position related data to a central controller.
. ~ , Still further included within the scope of the present invention is a method of causing a multi-shot blastin~ operation of a serles of explosive charges sr~c~ apart from eac~ o~er at a blast s;te, said rnetltod including the ste~s of:
- automatically deterrnlning position related data at each chars~e locatian;
- dete-- ,inins from the posltional data a requir~d firing sequence;
and ~

- applying ~ fiAn~ sequenc~ to ~e series o~ charges.
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The automatic determinatio n of position related data at each charge 10 location may be ob~ained using one of: a radio device; an acoustic device;
an optical device; a la~-r operated d-vlce; or a global positionir~3 system receiver.

' The posi~on related data may be determ;ned by absolute position 15 monitoring. Alternativaly, the position related data may be determined by distance-related monitoring.

, ., The requir~d firing sequence may be de2ermined from the positiona1 data by manual or automa~ic inputting of the data to a dala store.

The data store may be connec~d to, or incorporated in a remote controller which is operative to send sequential firing signals to the individual charses accord;na ~o ~he required firin~ sequence. Alternatively, the data store may supply rest ecti~e finrtg seq1lence data to individual local con~rollars associa~ed one with each char9e, 2nd upon issue of a common firing signal to ~he local controllers, sequential firing of the char~es takes place accordiny to the required firing sequence.

Accordin~ to another aspect of the invention There is provide~ an e~Yrlcsive firing system incll~ding:
- a plurality of detonators, - ~ a central con~roller for controHing operation of the detona~ors;
- position deter~ g means for determinin~3 position relate~
data for each of a plura!ity of suitable positions for the - detonators in a blast area;
- - the central controllor being arranged to utilize said position related data TO compute a blast pro~.a."",e;
- rneans for transferring signals relating to the blast proyra~ le To the detonators to cause them to detonate in accordance with the blast pro~ramme.

The cont-Jller, in computing the blast progfL...",e, may compute for each 20 position, delay time data relatin~ to a delay time from reception of a common fire siSanal after which a déTonator at that position must cause an assoc;ated charge To eYplo~ie The system may further incl~de means for inp~tting identiflcation code data ~ssoc;-ted wi~h each detonator. The means for inputting the iden~ficati~n code data may include a bar code reader for readin~ a ba- cod2 ~d~La~l~
~ppl~ed on each d~tcndto-. In another embodiment the identificabon code 5 data may be read electrcnicz~lly from a memory arrangement formin~3 part of the detonator.

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The positic~n d~ ..i,.ing means is preferably automatic position data deter".inin~ means and may includ~ a global positioning system (GPS) 10 incl~ding a GPS receiver cooperating with at least one earth orbiting satellite. In oth~r embodiments the position determining means may include a radio device, an acoustic device, an optical device or a laser oper2ted device.

15 The position determining means may be mo~nted on a boring machine for drilling holes wherein the detonators and asSociaTed e~tplQsive char~es are to be positioned. ~Iternativ~ly, it may be mounted on a vehicle transportin~3 the e~-rlcsive charges and detonators. Further alternatively, it may be carried in a carrie- or harness mountable on the body of a person 20 preparing the blast site.

The system may further include a data capturin~ dev;ce for receiving position related data and identification code data at the detonator positions and wh~ch device is connectable to the central controller for downloading said data Into the central controller. The central controller is preferably adaptad automaticaJly to determine ~he blast programme by inputting the posibon-related data there into. -~ :
The means for transfemn~ the delay time data and/or an cnergizing signal and/or the fire signal or signals may include a wired or f;~er cammunication path, alternatively it may c~mprise a wireloss, more particularly ra~io frequency (RF3 communication system.
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BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS
The invention will now further be described, by way of example only, with reference to the accompanying diagrams wherein:
fi~ure 1 is a diagrammatic plan view of an open-pit mine showing a plurality of holes drilled therein to receive explosive charges and with an imaginary grid superirnposed thereon, to indica~e the position of each hole;
fiyure 2 is a block dia~ta,~- of a first embodiment of a firins system ~ according to the inven~ion;
~0 figure 3 is a block diagram of a detonator forming parl of the system;
and figure 4 is a block diagram of an alternative embodiment of the system according to the invention.

' ' ' ''~ ', D~SCRIPTION OF A I ,~..~RED EIUBQDIN~ENT OF THE INVElYT~

An ope~pit mine is generally designated by the reference numeral 10 in figur~ 1. - -Multi-shot blastinsl tschniques are used not only to break up earth layers to a level close to a reef or the like to be mined, but also to move the broken-up ground away from the reef, to exp~se the reef. To accomplish this, positionin~3 of holes for receiving the explosives and Inter-hole delay times, 10 that is d~lay times between shots in the blast, nesd careful plannin~.

In the method according to the inven~ion, positions for the holes 12.1 to 12 8 are selected in situ. The holes a-e then drilled by a su;table ~oring machine to a required depth. The d~pth of the holes may differ from ono 15 ano~her depending on th~ geo!ogicaJ structure of the earth below the sur~ace.

Detonators 14.1 to t4.8 Ishown in figure 2~ are then inserted into holes 12.1 to 12.8 respectively and the holes are stemmed with expJosive 20 charges. The detonators are iden~ical, except that each is associatcd with a prepro6rammed identification code ~DET #1 to DET $8) individual thereto.

In an abs~lute position monito~ng step pas~ion related data, more pa~ticuiarly data r~6Li-,~ to pos~tion co-ord~ tes of the holes (~,;y~) etc, are det~r"..ned automatic~l~y in known manner, Ltili2in~, for example, a Global Position;ng System (GPS) comprising a GPS receiver 19 (shown in fi~ure 2) 5 and a network of earth orbitin~ satellites. The GPS receiver may be mounted on the boring machine or a vehicle carrying the ~Ypl~sive charges and detonators or fn a suitable carrier or harness for the ~eceiver mou~ntable on the back of a person prepa~;ng the holes. In oth~r embodiments, the posi~ion related data may be deterrnined by tistance related monitorfng, 10 more partfcularly by deter-,.i.~ing inter-hole d;stance-rela~ed data, by utilizing, for example, one of a radio device, an acoustic devlce, an optical device or a laser operated device.

In a further s~ep, the identification numbers of the detonators 141 to 14.8 fn each of the holes 1 2.1 to 12.8 are determined, for example by electronically reading it or preferably by reading it passively, for example by reading by means of a bar code reader 36, 8 bar code pattern 34 on the body or a connector (not shown) of ~lie detonator. The identlty number of the detonator, the GPS data of the hole, d. ta regarding tlie depth of the 20 relevant hole, data regardin~ the type and mass of explosive in the hole and data re~J. cli~ eclo~ic~l - structure are captured in a porta~le data capturing device 18. The device 18 is connectable to the bar code reader 36 to receive the idenbty number, to GPS receiver 19 to receive the positlon data and als o to c~ l contr~lbr 16, to downJoa<i the aforementioned data, As stated hereinbefore, the detonators are identical except for their 5 iden~ficabon numbers. Accordin~ly, only detonator 14.1 will be described hereinafter with reference to figure 3. Detonator 14.1 comprises a read only memory arrangement (ROM) 22 -tonng the preproS,- dn .n~ed identification code (DET #1) indivWual thereto, a local timer 24 for timing out a delay time, data regardin~ which is loaded and stored in the 1 O detonatar as will hereinafter be describ~d, a capacitor 26 for storing electrical charge and a switching arrangement 28 which, when activated by a local controller 30, ca~ ~ses charge stored on the capacitor to bc dumped into a fusehead 32, such as ;!~semiconductor bridge (SCB). The local controller comprises random access memory (RAM) for storing the 15 aforenlentioned delay time data associated with detonator 14.1.

In the embodiment shown in fi~ure 2, ~he controller 16 is connected by electrical wires 20 to the detonators 14.1 to 14.8.
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20 As stated hereinbefore, ~he data cap~uring device ~ 8 is connectable to controller 16. The GPS data, ID code data and the other da~a referred to hereinbefore stored in t~he data-capturing device 18 are downlo?~ into the con~roller 16. The controller 16 then utilizes the GPS data, the ll~ code data and the da~a reg~ cliny the type of e~plo~;ve us~d, the mass of oYrlosive per hole, depth of tho hole and ~eological data to compute d~ay time pro~r..i....le, compnsing del-y times, preferably from a common fire signal, for each of the hole positions.

An enery~ ~ signal is ~_n..~,-ilLed on the line 20 to charge the capacitor 26 of each detonator. Thereafter, data regarding the delay times is .
t(~sl.,itted on line 20 to the respective detonators at the relevant holes, utilizing the relevant idenbfic~tion codes of the detonators at the hotes as 10 addresses The delay time data is stored in the RAM of each local contraller 30.

The next step io to ~(allsltlil a common fire signal on line 20 to all the detonators simultaneously. The local bmers 24 in each o~ the detonators 15 then time out the delay umes stored in the RAM and associated with the detonator, before the local controller 30 c~l~ses the switch 28 to close, to cause the charge in the capacitor 26 to be dumped in the fuse, to activate the detonator, to cause the associated eYrlesive charge to explode as part of th- rnulti-shot blast.

In the embodiment shown in figure 4, the electrical communication line 20 is rerl~ce~l by a radio frequency (RF) liAk. The controller 116 comprises a RF tra,.s.,.itter (not shown) and antenna 38 and each detonator 114 1 to 114.8 camprises a RF receiv~r (n~t shown) and an antenna 40.1 to 40.8 resl~ectively. In tl~is ernbod~ment thc bar code reader 8nd data capturing device may be incorporated in a sinS}le portable unit 36. The unrt 36 is connectable to the controller 116 and the GPS receiver 19 is connectable to 5 the unit 36, to download the GPS data.

In this e---L.GJi.,.ent the ~.-er~;~ing signal, the delay time data and ~he common fire signal are t.ans!";Lled via ~he RF link.

10 In another embodiment of the method, the posi~ion related data is inputted manually or automatically into a central controller. Upon such inputting of the data, the controller automatically determines the firing se~luence and delay times. The delay times are then timed out by the controller ~which prefera~7ly is remote from the de~on~tors and associated charges) and fire 15 signals are transmitted sequentially by the controlle- to Ihe dstonators in accordance with the desired firing sequence.

It will be appreciated that there are many variations in detail on the eYplQsive firing system and method according to the invention without 20 departin~ from the spirit of the appended claims.
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Claims (31)

1. A method of causing a multi-shot blast including the steps of:
- selecting a plurality of spaced positions for locating detonators in a blast site;
- at each position, determining position related data for that detonator position;
- utilizing the position related data to establish a blast programme; and - providing signals to detonators at the detonator positions to cause them to detonate according to the programme.

2. A method as claimed in claim 1 also including the step of determining identification code data of each of the detonators before establishing the blast programme.

3. A method as claimed in claim 2 wherein the identification code data is determined by reading the data electronically from a memory arrangement forming part of the detonator.

4. A method as claimed in claim 2 wherein the identification code data is determined passively.

5. A method as claimed in claim 4 wherein the identification code data is provided in the form of a bar code pattern on the detonator and wherein the bar code pattern is read by a bar code reader.

6. A method as claimed in any one of claims 1 to 5 wherein the position related data is determined by determining distances between the detonator positions.

7. A method as claimed in any one of claims 1 to 5 wherein the position related data is determined by determining position coordinate data for each detonator position,

8. A method as claimed in claim 7 wherein the position coordinate data is determined utilizing a global positioning system (GPS) including a GPS receiver and at least one earth orbiting satellite.

9. A method as claimed in any one of claims 2 to 8 wherein the position related data and identification code data are captured in a data reading, storing and downloading device.

10. A method as claimed in claim 9 wherein the captured data is downloaded into a central controller for establishing the blast programme.

11. A method as claimed in any one of claims 1 to 10 wherein the step of providing signals to the detonators includes the step of transmitting to each of the detonators, utilizing its respective identification code data as an address, delay item data relating to a delay time from a common fire signal for each detonator to detonate.

12. A method as claimed in claim 11 wherein before the delay time data is transmitted to the detonators, the detonators are energized by transmitting an energizing signal to the detonators.

13. A method of timing a multi-shot blast including the steps of:
- locating a detonator arrangement including a detonator having a preprogrammed identification code; and an associated explosive charge, in each of a plurality of spaced detonator positions;
- at each position, determining respective detonator identification code data relating to the detonator at that position and respective position related data for that detonator position;
- transferring the respective detonator identification code data and respective position related data to a central controller;

- computing for each detonator position, data relating to a respective delay time from reception of a common fire signal after which the detonator at that detonator position must cause its associated charge to explode;
- utilizing the respective detonator identification code data and transmitting the respective delay time data to each detonator at said detonator positions; and - transmitting a common fire signal to each detonator, to cause its associated charge to explode after the respective delay time computed for that detonator position.

14. A method of preparing a blast site, the method including the steps of:
- selecting a plurality of spaced positions for locating electronic detonators;
- at each position determining position related data for that detonator position; and - transferring the position related data to a central controller.

15. A method of causing a multi-shot blasting operation of a series of explosive charges spaced apart from each other at a blast site, said method including the steps of:
- automatically determining position related data at each charge location;
- determining from the positional data a required firing sequence;
and - applying the firing sequence to the series of charges.

16. A method according to claim 15, in which the automatic determination of position related data at each charge location is obtained using one of: a radio device; an acoustic device; an optical device; a laser operated device; or a global positioning system receiver.

17. A method according to claim 16, in which the position related data is determined by absolute position monitoring.

18. A method according to claim 16, in which the position related data is determined by distance-related monitoring.

19. A method according to any one of claims 15 to 18, in which the required firing sequence is determined from the positional data by manual or automatic inputting of the data to a data store.

20. A method according to claim 19, in which the data store is connected to, or incorporated in a remote controller which is operative to send sequential firing signals to the individual charges according to the required firing sequence.

21. A method according to claim 19, in which the data store supplies respective firing sequence data to individual local controllers associated one with each charge, and upon issue of a common firing signal to the local controllers, sequential firing of the charges takes place according to the required firing sequence.

22. An explosive firing system including:
- a plurality of detonators;
- a central controller for controlling operation of the detonators;
- position determining means for determining position related data for each of a plurality of suitable positions for the detonators in a blast area;
- the central controller being arranged to utilize said position related data to compute a blast programme;

- means for transferring signals relating to the blast programme to the detonators to cause them to detonate in accordance with the blast programme.

23. A system as claimed in claim 22 wherein the controller in computing the blast programme computes for each position, delay time data relating to a delay time from reception of a common fire signal after which a detonator at that position must cause an associated charge to explode.

24. A system as claimed in claim 22 or claim 23 also including means for inputting identification code data associated with each detonator.

25. A system as claimed in any one of claims 22 to 24 wherein the position determining means includes a global positioning system (GPS) including a GPS receiver cooperating with at least one earth orbiting satellite.

26. A system as claimed in any one of claims 22 to 25 also including a data capturing device for receiving position related data and identification code data at the detonator position and for downloading said data into the central controller.

27. A system as claimed in any one of claims 22 to 26 wherein the signal transferring means includes a wired communication path between the controller and the detonators.

28. A system as claimed in any one of claims 22 to 26 wherein the signal transferring means includes a radio frequency link between the controller and the detonators.

29. A method of causing a multi-shot blast substantially as herein described with reference to the accompanying diagrams.

30. A method of timing a multi-shot blast substantially as herein described with reference to the accompanying diagrams.

31. An explosive firing system substantially as herein described with reference to the accompanying diagrams.