Wireless detonator consolidation

Abstract

A wireless detonator system which includes groups of detonators at a blast site, wherein a unique key is transferred to each detonator in a group which is tagged by a tagger which transmits data on the tagged detonators to a data collection point at which identifiers of the tagged detonators are compared to a master blast plan to identify inconsistencies between the tagged detonators, at the blast site, and detonators which are recorded in the master blast plan.

Description

BACKGROUND OF THE INVENTION

[0001] This invention relates to a wireless detonator system and to a method for enhancing the reliability of operation of the system.

[0002] A number of potential problems exist in a wireless detonator system, particularly if the wireless detonators are essentially unidirectional in nature and are not able to transmit return signals over a meaningful distance, for example, to a blast controller.

[0003] A large number of wireless detonators can be deployed at a blast site and it is important, taking into account safety considerations and effectiveness of operation, to ensure that all detonators at the site are accounted for and are correctly installed and tagged before blasting takes place. External factors such as noise sources, geographical features and detonator positions can adversely affect the capability of a detonator to be incorporated effectively into a blast network.

[0004] In one technique, in the implementation of a wireless detonator system, a blast plan is distributed to multiple mobile taggers. Each tagger is used to tag a subset of the detonators in the system. The accurate collation of data from all the taggers is essential for effective blast operation. Unpredictable and unforeseen factors can adversely influence the process. For example, some detonators can be omitted from the tagging exercise because of their absence due to boreholes not having been drilled or having collapsed. Another aspect to be addressed is the capability of a tagger to tag unplanned detonators i.e. detonators which initially were not included in a blast plan.

[0005] Also, at a large site, a number of taggers are employed and the collection and ordering of information from all of the taggers in a reliable manner so as to ensure that all detonators are accurately accounted for can be problematic. A failure to meet this requirement can lead to one or more of the detonators at the blast site not being included into a final blast plan and, consequently, these detonators would not be fired when the other detonators in the plan are fired.

[0006] Conversely a detonator which is not a part of an original blast plan could be tagged and upon receipt of a fire command signal would be ignited, but not necessarily at a desired time.

[0007] It is desirable therefore to be able to consolidate information on all tagged detonators with information in a blast plan before firing. All detonators can then be accounted for before technicians leave the blast site and prior to basting taking place.

[0008] An objective therefore is to allow for the collection and consolidation of information relating to detonators at a blast site whereby data, pertaining to an original blast plan, can be compared to data obtained from onsite tagging in a process which allows for anomalies such as detonators which are included in an original blast plan but which are absent from a blast site, and for detonators which are present at a blast site but which are absent from a blast plan, to be identified by personnel who are at the bench and who are capable of taking remedial action directly, at that time. Information of the remedial action taken can then be transmitted via a network to a central point. This capability must be contrasted with an approach wherein corrective action in respect of an anomaly or variance is taken subsequently (i.e. not when detected) at a location which is at a place of people safety and which is removed from the bench.SUMMARY OF THE INVENTION

[0009] The invention provides a method of consolidating information on a wireless detonator system at a blast site wherein the detonator system includes a blast controller, a plurality of repeaters which are responsive to wireless signals from the blast controller and a plurality of detonators which are responsive to wireless signals from respective repeaters, the method including the steps of storing in a first device an original blast plan for the blast site, wirelessly transferring the original blast plan plus a key which is unique for the detonator system to each of a plurality of secondary devices, using each secondary device to tag each detonator in a respective group of detonators at the blast site and to transfer the unique key to each tagged detonator, producing in each secondary device a list of the detonators to which the unique key was transferred (“the tag list”), wirelessly transferring the respective tag list from each secondary device to a data collection point, and comparing said tag lists, transferred to the data collection point, to the original blast plan stored in said first device to identify inconsistencies between the tag lists and the original blast plan.

[0010] Notification of an inconsistency which is identified as aforesaid is forthwith sent at least to the relevant secondary device so that, at the time, an operator of the secondary device can take remedial action at the appropriate location on the blast site.

[0011] The first device, which may be a tagger or similar apparatus, is referred to herein as a master tagger.

[0012] Each secondary device, which may be a tagger or similar apparatus, is referred to herein as a slave tagger.

[0013] Preferably the data collection point is at or embodied in the master tagger. This however is not essential for the data collection point could be one of the repeaters or one of said slave taggers, or could be a separate mechanism established and used for this purpose.

[0014] The blast site includes a number of boreholes and each borehole is associated with at least one detonator which is installed in the borehole at an appropriate stage during the development of the blast system.

[0015] Groups of the detonators, i.e. subsets of the detonators, may be responsive to wireless signals from different repeaters. However some detonators in one subset which are responsive to wireless signals from a first repeater may also be responsive to wireless signals from a second repeater which, in turn, is used primarily to transmit wireless signals to all of the detonators which are in another subset.

[0016] Each slave tagger is used to tag a subset of the detonators at the blast site. The unique key is used as an indicator to designate those detonators which are included in the blast plan.

[0017] Each slave tagger may include a capability to tag unplanned detonators i.e. detonators which were not originally included in the blast plan. Conversely, a detonator, included in the original blast plan, may be omitted from a tag list which is produced by a tagger, for various reasons. For example a borehole for the detonator in question may not have been drilled, or the borehole may have collapsed or the omission could be due to some other cause.

[0018] An inconsistency between a tag list and the blast plan is related to a detonator and gives rise to information which allows the location of the detonator i.e. of the borehole in which the detonator is or was to be placed, to be ascertained. Data pertaining thereto is transmitted to the slave tagger so that the operator thereof can take remedial action as appropriate.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is further described by way of example with reference to the accompanying drawings in which:

[0020] FIG. 1 schematically illustrates a wireless blasting system, and

[0021] FIG. 2 shows how the method of the invention can be implemented in a wireless blasting system of the type shown in FIG. 1.DESCRIPTION OF PREFERRED EMBODIMENT

[0022] FIG. 1 of the accompanying drawings illustrates a wireless blasting system 10 which is implemented at a blast site 12. The site 12 can be of considerable size and, in this event, the blasting system 10 may include a substantial number of detonators 14. Each detonator 14 is installed using techniques known in the art in a respective borehole, not shown. The detonators 14 are in groups 16 nominally encompassed in a respective circular area, and each group is responsive to signals from, at least, a respective repeater 20. The repeaters are capable of two-way communication with a blast controller 24. The resulting network has a star topology with the blast controller 24 at the top of the star.

[0023] If the blast site 12 is extensive in area and there are a large number of detonators then it can be difficult to ensure that all detonators in the system are accounted for i.e. identified and included, correctly, in a blast plan for firing. FIG. 2 illustrates a method according to the invention for achieving this objective.

[0024] FIG. 2 illustrates a master tagger 30 which could, in one embodiment, be in the blast controller 24, and a number of secondary or slave taggers 32 which are mobile devices and which are carried by respective operators, not shown. Each slave tagger 32 is capable of bidirectional communication directly or indirectly with the master tagger 30.

[0025] In FIG. 2, for clarity purposes, the repeaters 20 and the blast controller 24 are not shown. These components do however form an integral part of the arrangement in FIG. 2.

[0026] An original blast plan 40 for the blast site is created or is otherwise stored in the master tagger 30 together with a key 42 which is unique to the blasting system 10. The key 42 is used to designate all detonators 14 which are included in the original blast plan 40. The original blast plan 40 and the key 42 may initially be in the blast controller 24 and are subsequently transferred to the master tagger 30, if separate from the blast controller 24, when necessary. Details of the original blast plan 40 and the key 42 are transmitted to each of the slave taggers 32. This is done wirelessly using short-range communication techniques by means of signals sent from the master tagger, or from the blast controller 24 directly to the slave taggers, or sent to the slave taggers via the relevant repeaters 20. Each slave tagger 32 is used by an operator to tag detonators 14 which are identified in the original blast plan and which are included in a specific area 16 which is associated with the slave tagger. Each detonator 14 is capable of bidirectional communication, for example using a top box or a suitable short range communication technique, with the respective tagger. “Tagging” involves various operations such as identifying a detonator, programming the detonator, assessing the installation condition of the detonator, and so on.

[0027] Any anomalies in an area 16 are dealt with at the time. Such anomalies may include a detonator which has not previously been considered for inclusion in the original blast plan, and a detonator which is to be omitted from the original blast plan due to physical causes at the bench.

[0028] The groups 16 are shown as covering precise circular areas. This is only representative. Due to blasting requirements and geographical features signals, from a first repeater, which are primarily intended for a first group of detonators may reach one or more detonators which are regarded as being in a second group. Also, a slave tagger may be used in an attempt to tag a detonator which has already been tagged by the same or a different tagger. This type of overlapping is catered for, at the time on the bench, in that details of the original blast plan and of the key are sent to all of the slave taggers.

[0029] Details of all of the detonators which are tagged at a specific area 16 by the respective slave tagger 32 are stored by the slave tagger 32 in what is referred to as a tag list 46 which is associated with that tagger. The tag lists 46 from the various slave taggers 32 are then transmitted, directly or via the repeater or other intermediate devices, to the master tagger 30 using wireless techniques. The incoming data taken from the tag lists is consolidated by the master tagger which then effects a comparison between the consolidated data and the data in the original blast plan 40. Information on any inconsistency resulting from the comparison is included in an output signal 50 sent to an operator on the bench so that appropriate remedial action 52 can be taken. By way of example only, inconsistencies can be attributed to the inclusion in a tag list of an unplanned detonator or, conversely, the exclusion for some reason of a detonator which is in the blast plan 40 but which is not in the consolidated assembly of tag lists.

[0030] Although reference has been made to the master tagger 30 as the mechanism through which consolidation is done this is exemplary only. Any of the slave taggers 32 could be used for this purpose and so could a repeater 20 or an external computing device (not shown) which may be embodied in, or associated with, the blast controller 24.

[0031] A benefit of the process described is that the consolidation exercise is implemented basically in real time during installation and tagging procedures of the detonators. This allows for inconsistencies to be identified and remedied at the time of deployment or tagging. Also, the method of the invention helps to reduce the likelihood that detonators, scheduled to be a part of the original blast plan, could be omitted therefrom or, conversely, that detonators could unintentionally be included in the blast plan.

[0032] The process described results in an “as tagged” blast plan which includes all the information flowing from the slave taggers. This “as tagged” blast plan is compared to the master or original blast plan and anomalies (points of variance) are identified. Typically an anomaly relates to a detonator which is identified in the original blast plan but which is absent from the bench, or a detonator which is at the bench but which is not listed in the original blast plan. The anomaly is dealt with directly at the time on the bench by a technician who is notified via the tagger / repeater network. Information on the corrective step taken by the technician is transferred in the reverse direction by the tagger / repeater network to modify the original blast plan 40 and so produce an up-to-date or “live” blast plan which more accurately details the detonators which are actually deployed at the blast site.

Claims

1. A method of consolidating information on a wireless detonator system at a blast site wherein the detonator system includes a blast controller, a plurality of repeaters which are responsive to wireless signals from the blast controller and a plurality of detonators which are responsive to wireless signals from respective repeaters, the method including the steps of storing in a first device an original blast plan for the blast site, wirelessly transferring the original blast plan plus a key which is unique for the detonator system to each of a plurality of secondary devices, using each secondary device to tag each detonator in a respective group of detonators at the blast site and to transfer the unique key to each tagged detonator, producing in each secondary device a list of the detonators to which the unique key was transferred (“the tag list”), wirelessly transferring the respective tag list from each secondary device to a data collection point, and comparing said tag lists, transferred to the data collection point, to the original blast plan stored in said first device to identify inconsistencies between the tag lists and the original blast plan.

2. A method according to claim 1 wherein the first device is a tagger and the second device is a tagger.

3. A method according to claim 1 wherein notification of an identified inconsistency is sent to the respective secondary device to allow for remedial action, to address that inconsistency, to be taken at that time on the blast site.

4. A method according to claim 3 which includes the step of modifying the original blast plan with data pertaining to said remedial action to produce a revised blast plan which more accurately details the detonators at the blast site.

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