Title of Invention

METHOD FOR EXCHANGING DATA BETWEEN ELECTRONIC DETONATORS AND A DETONATOR PROGRAMMING AND TRIGGERING DEVICE

Abstract

The invention relates to a method for exchanging data between electronic detonators and a detonator programming and triggering device, wherein a plurality of electronic detonators are disposed one behind the other in an ignition circuit, an address is assigned to each of the detonators, the detonators are triggered in a specifiable delay sequence and the data are generated by a time sequence of signals having a specified voltage, characterized in that, prior to an intended communication of a detonator with the device, there is applied to the ignition circuit for a specified time a direct voltage that is higher than the voltage provided for signal generation, wherein the signals with which the data are generated that the detonator transmits as a response are then generated at a lower voltage than the previously increased voltage, and wherein, prior to the response of a further detonator, the direct voltage is increased again.

Full Text

This invsntion relates to a method for exchanging data between a device for programming and triggering electronic detonators and the detonators in accordance with the preamble of the first claim. In the extraction of raw materials deposited in the earth, it is necessary to clear away rock masses preventing access to the raw materials and then to obtain the raw materials from their deposits by crushing. During this excavation method, explosions are carried out in which explosive charges disposed in many boreholes are detonated conaecutively in accordance with a certain time schedule. A method of controlling explosion detonators and a so-called coded structure for controlling the blasting are disclosed, for example, in EP 0 588 685 Bl. The electronic detonators of the explosive charges form an ignition system. The electronic detonators are commonly connected to a programming and triggering device via a so-called bus line. Via said bus line, the electronic detonators are activated and receive electrical energy that is capacitively stored by them. If the capacitance of a detonator is charged, it is capable of independently remaining in operation with the aid of the energy stored in its capacitor. The stored energy safeguards the ignition function and also the communication function between the detonator and the programming and triggering device of the detonators. As a rule, every individual detonator has an address that is assigned to it and comprises a multidigit digital code. The delay time that determines the instant ac which the respective detcnator is detonated ie transmitted in the form cf coded signals to every individual detonator. The signals may consist of a polarity change of a specified voltage having a specified amplitude. The delay time is coupled to an address code so that every detonator charges only for the delay time assigned to it on the basis of the address code. After the detonator has received the transmitted data assigned to it, it has to respond so that it is possible to confirm that the delay time has been received and stored correctly by the electronics of the detonator. During the communication of a detonator with the programming and triggering device of the detonator, problems occur in that the other detonators connected to the bus line are capacitive resistances that affect the transmission of the data. The data signals comprise, as a rule, a polarity change in a certain time sequence and in a certain number. These polarity changes are distorted by the capacitive resistances so that a clear transTOiaaion of the signals is not always guaranteed. Taking into account the capacitive resistances, the data transmission rates per unit time are low and the programming of a detonator, which takes place in the dialogue of the electronics of the detonator with the programming and triggering device of the detonators, is time-consuming and not always fault-free. The object of the present invention is therefore to make the exchange of data between an electronic detonator programming and triggering device and the detonators more reliable and more rapid. The object is achieved with the aid of the characterizing features of the first claim. Further advantageous refinements of th^ invention are claimed in the subclaims. According to the invention, prior to an intended communication of an electronic detonator with the detonator progratnining and triggering device, there is applied to the ignition circuit for a specified time a direct voltage that is greater than the voltage of the signals with which the data are generated that the detonator transmits as a response. The increased voltage is below a critical voltage for triggering a detonator. As a rule, the detonatora are designed in such a way that they are resistant, i.e. are not triggered, to a voltage that is at a certain height above the nominal voltage provided for generating the signals for communicating with the detonators. According to the invention, the tolerance range provided is, however, not exhausted in order to avoid any risk. On the other hand, the amplitude of the voltage is chosen in such a way that the capacitances of the other detonators are charged within a very short time to such a level as to avoid an attenuation of the voltage with which the detonator response signals are generated. To transmit the detonator response, the voltage is reduced and the signals of the data that the detonator transmits as a response are generated at a lower voltage. During the transmission of the signals of the responding detonator, all the other detonators are charged to such a high level that they are no longer capacitive resistances and communication is thereby possible at a very high data transmission race per unit time. The voltage in the ignition circuit is increased during such a time to auch a value that, during the subsequent detonator response, capacitances of the other detonators do not have to be charged as a result of charge losses. The magnitude of the capacitive and ohmic resistances within the ignition circuit depends on the nutirf)er of connected electronic detonators. In a turther advantageous refinement of the invention, it is possible that the capacitive resistance is ascertained and the minimum direct voltage necessary to charge the capacitances is determined as a function of its magnitude. In addition, the voltage drop due to the ohmic resistances can be compensated for. The increase m the direct voltage can consequently be matched individually to the particular application case. In addition, this ensures that the voltage does not exceed a critical value that results in the triggering of a detonator. Accordingly, the present invention provides a method for exchanging data between electronic detonators and a detonator programming and triggering device, wherein a plurality of electronic detonators are disposed one behind the other in an ignition circuit, an address is assigned to each of die detonators, the detonators are triggered in a specifiable delay sequence and the data are generated by a time sequence of signals having a specified voltage, characterized in that, prior to an intended communication of a detonator with the device, there is applied to the ignition circuit for a specified time a direct voltage that is higher than the voltage provided for signal generation, wherein the signals with which the data are generated that the detonator transmits as a response are then generated at a lower voltage than the previously increased voltage, and wherein, prior to the response of a further detonator, the direct voltage is increased again. The invention is explained in greater detail by-reference to a replacement circuit diagram. The replacement circuit diagram of an ignition circuit is denoted by 1. A bus line 3, represented by two line conductors 3a and 3b, is routed from Che detonator programming and triggering device 2 to the detonators 4a, 4b and 4c. Assigned to the detonators 4a, 4b and 4c are the respective charges 5a, 5b and 5c to be ignited. The three electronic detonators ahown represent any desired number of detonators that are connected to the bus line 3 to fulfil the respective requirement, said bus line 3 makes possible a bidirectional data transmission, that is to say from the detonator programming and triggering device 2 to the detonators and back from the detonator electronics to the device 2. The length of the bus line 3 and the detonator electronics cause a voltage drop within the ignition circuit 1 and this is represented by the ohmic resistances denoted by 7a, 7b and 7c. Capacitors that are intended to represent the energy stores of the respective detonators are denoted by Ba, 8b and 8c. The energy stored in them makes possible communication between the detonators 4a to 4c and the detonator programming and triggering device 2. In addition, the stored energy serves to trigger the detonators. To ensure the ignition of the individual detonators 4a to 4c and the detonators not shown in further detail here in addition in the planned sequence at the planned instants, it is necessary for every detonator to receive a communicated delay time assigned to it. Each of the detonators 4a to 4c has an address stored in its electronic circuit 6a. to 6c. Said address comprises a coded signal, a signal containing a specified number of polarity changes in a specified time. The data are transmitted by a voltage having a certain amplitude that is supplied by the voltage source 9. In order to ensure the transmission of the data, the respectively addressed detonator responds when it has received the data correctly with the delay time provided for it. To overcome the capacitive resistance, the voltage of the voltage sou.rce 9 is increased prior to the detonator's response for a specified time to such an extent that the capacitances of the other detonators are charged to such an extent that, at the instant when the detonator responds, no capacitances of the other detonators have to be charged as a result of charge losses in the capacitances. Consequently, the other detonators do not represent for the responding detonator capacitive resistors that impair the quality of the response signals. The response of the responding detonator takes place at a lower voltage level than the previously increased voltage level. For the reasons mentioned above, a fault-free transmission of the signals of the detonator takes place to the detonator programming and triggering device 2. Once the responding detonator has transmitted its response and a subsequent detonator is to respond, the voltage is also increased in the ignition circuit prior to its response so that the signal transmission is not impeded by capacitive resistances during the subsequent response. Prior to switching to a higher voltage, it is possible that, in accordance with the present exemplifying embodiment, the capacitive resistance and the voltage drop in the ignition circuit 1 are ascertained by means of a test device that is denoted by ID and is connected via the lines 11 and 12 to the line conductors 3a and 3b, respectively, of the bus line 3. These values are transmitted via the line 13 to the detonator programming and triggering device 2, To overcome the capacitive resistance and to charge the capacitances, a higher voltage is then applied to the ignition circuit 1 for a specified time than is necessary to generate the daca signals that Che detonator transmits as a response. As a result of the fact that the effect of the capacitive resistances in the ignition circuit 1 is eliminated prior to every response of a detonator, a fault-free communication is possible between the detonator programming and triggering device 2 and the detonators 4a to 4c at a high signal tranemiasion rate. WE CLAIM: 1. A method for exchanging data between electronic detonators and a detonator programming and triggering device, wherein a plurality of electronic detonators are disposed one behind the other in an ignition circuit, an address is assigned to each of the detonators, the detonators are triggered in a specifiable delay sequence and the data are generated by a time sequence of signals having a specified voltage, characterized in that, prior to an. intended communication of a detonator with the device, there is applied to the ignition circuit for a specified time a direct voltage that is higher than the voltage provided for signal generation, wherein the signals with which the data are generated that the detonator transmits as a response are then generated at a lower voltage than the previously increased voltage, and wherem, prior to the response of a fiirther detonator, the direct voltage is increased again. 2. The method as claimed in claim 1, wherein the voltage in the ignition circuit is increased for such a time to such a value that, during the subsequent response of a detonator, none of the capacitances of the other detonators is being charged as a result of charge losses. 3. The method as claimed in claim 1 or 2, wherein the increased voltage is below a critical voltage for triggering a detonator. 4. The method as claimed in any one of claims 1 to 3, wherein the capacitive resistance in the ignition circuit is ascertained and the direct voltage at least necessary for charging the capacitances is determined as a function of its magnitude. 5. The method as claimed in any one of claims 1 to 4, wherein the voltage drop due to the ohmic resistance in the ignition circuit is ascertained and the voltage is determined that is necessary to compensate for the voltage drop. 6. A method for exchanging data between electronic detonators and a detonator programming and triggering device, substantially as herein described with reference to the accompanying drawings.

Documents:

in-pct-2001-1299-che abstract.pdf

in-pct-2001-1299-che claims.pdf

in-pct-2001-1299-che correspondence-others.pdf

in-pct-2001-1299-che correspondence-po.pdf

in-pct-2001-1299-che description(complete).pdf

in-pct-2001-1299-che drawings.pdf

in-pct-2001-1299-che form-1.pdf

in-pct-2001-1299-che form-19.pdf

in-pct-2001-1299-che form-26.pdf

in-pct-2001-1299-che form-3.pdf

in-pct-2001-1299-che form-5.pdf

in-pct-2001-1299-che pct.pdf

in-pct-2001-1299-che petition.pdf