EP0588685B1 - Programmable integrated detonator delay circuit - Google Patents

Description

The present invention relates to a method for controlling detonators of the type with an integrated electronic delay ignition module, as well as to a coded firing control assembly and to coded ignition modules for its implementation.

In most explosive work, the detonation of the charges is caused according to a very precise time sequence, this in order to improve the work performance of the explosive and to better control its effects.

Conventionally, the various delay times between the explosions of the charges are obtained by a pyrotechnic process at the level of the detonators themselves. The detonators are initiated simultaneously by an exploder which delivers a certain electrical energy in a firing line which connects said detonators in series or in parallel.

However, the pyrotechnic delay generated by the combustion of a retarding pyrotechnic composition is of relative precision sometimes insufficient for certain applications.

To overcome this drawback, it has recently been proposed to use electronic delay type detonator ignition devices, which make it possible to take advantage of the precision that it is possible to obtain in electronics to enrich and refine the delay time ranges previously obtained pyrotechnically. It has in particular been proposed in US patent 4,674,047 which is based on the preambles of independent claims 1 and 4, as well as in an article repeating a conference given by the inventors on the same subject, "The Development Concept of the Integrated Electronic Detonator - Worsey-Tyler - Society of Explosives Engineers - Proceedings of the 9 ^th Conference of Explosives and Blasting Techniques - 1983 January 31 - February 4 "detonators equipped with electronic means allowing them to communicate with an external control unit. Each detonator is equipped with a capacity whose discharge activates the explosive charge. The delay times of each detonator can be programmed on site, a identification code having been previously assigned to each detonator, for example at the factory.

The fire control unit is designed to be able to transmit identification information of delay times and other control information and signals. In addition, it displays the response of the detonators, following an interrogation made by the fire control unit, representing the identification and the delay time stored in memory for each of them.

During a firing sequence, the detonators receive successively loading orders from the firing control unit, then firing orders. They send information back to the fire control unit enabling the said control unit to control the proper conduct of the fire sequence. The detonators are provided for this purpose with local intelligence by microprocessor. The delay times for which they are programmed are stored on non-volatile memories.

The aim of the present invention is to propose a method for controlling electronic ignition modules with integrated delay, as well as a coded fire control assembly and a coded ignition module for its implementation, giving detonators the aforementioned advantages of detonators with integrated electronic delay, but also great simplicity of manufacture and operation.

The subject of the present invention is a method for controlling detonators of the type with an integrated electronic delay ignition module, each coded ignition module comprising a tank capacity intended, after loading, to discharge into a sound initiating head. detonator to generate an electric ignition pulse, a time base and a logic unit provided with a memory for storing in said ignition module an explosion delay time of said detonator, during 'A firing sequence, said ignition modules being able to communicate with a firing control unit intended to transmit to them in particular an order to load the tank capacity, as well as a firing order and to receive said modules one or information relating to their state, process in which, before a firing sequence, their delay time is memorized with a programming unit in the ignition modules.

According to the invention, the method is characterized in that, once the ignition modules have been programmed, the programmed delay times are transferred to the fire control unit using the programming unit, in that the firing control unit simultaneously interrogates the online ignition modules by a test command, before the loading step and the firing step and in that the ignition modules refer to the firing control unit global information relating to their state, according to a time sequence which corresponds to the firing time sequence.

The exchanges between the fire control unit and the ignition modules are done by means of coded binary messages.

The communications being supported by a two-wire line, the fire control unit and the ignition modules must be tolerant of the damage that the electrical signals can undergo during their transit on this line.

The messages transmitted to the detonator are coded in the form C (8,4).

After coding, a word formed of 4 bits of information is transmitted, on the transmission channel, in the form of an 8-bit message.

• de détecter la présence dans le message, d'une ou deux erreurs générées par des perturbations sur le canal de transmission,
• de reconstituer l'information de base dans le cas où le message ne contient qu'une seule erreur.

The introduction of 4 additional bits (control bits) allows the receiver:

• detect the presence in the message of one or two errors generated by disturbances on the transmission channel,
• to reconstitute the basic information in the case where the message contains only one error.

The code C (8,4), used for the present invention is constructed from a cyclic code C (7,4) to which a parity bit calculated as a function of the value of the other 7 bits of the message is associated.

After receiving a message, the ignition module goes through a decoding phase allowing the recovery of the 4 bits of information of this message. In the event that a detected error cannot be corrected, an error message is returned to the fire control unit.

• une commande,
• un retard + un numéro d'ordre.

Two types of messages can be received by the detonator:

• An order,
• a delay + a serial number.

When the ignition module is in the reception phase, it knows what type of massage will be transmitted to it. Indeed, any reception is preceded by the reception of an appropriate order.

After receiving and decoding a command, the logic unit of the ignition module proceeds to perform the appropriate function.

Advantageously, the time base of each ignition module is measured during programming of the corresponding module in time delay.

Preferably, the delay times are different for each module and the modules return the information requested after a feedback time depending on the delay time stored in each of them, said fire control unit opening for each of the modules reception time windows corresponding to said return time.

Preferably, the firing control unit simultaneously interrogates the online ignition modules by a test command, before the loading step and the firing step and the ignition modules return to the control unit. to draw global information relating to their state.

Another subject of the invention is a coded fire control assembly comprising a fire control unit and integrated electronic delay ignition modules for detonator, electrically connected in line to said fire control unit, and a fire control unit. programming.

The connection between the fire control unit and the ignition modules is used to power said ignition modules, as well as for dialogue between said fire control unit and said ignition modules.

The coded fire control assembly is characterized in that the ignition modules include means enabling them to send information to the fire control unit in the form of over-consumption of the line current, the unit of fire control being provided with means for detecting an overconsumption of the line current with respect to the average consumption of the ignition modules.

• chaque module d'allumage comprend une base de temps formée par un circuit RC;
• l'unité de programmation est apte à dialoguer séparément avec chaque module d'allumage, pour la mémorisation des temps de retard d'explosion dans lesdits modules d'allumage et l'unité de commande de tir est apte à transmettre les phases de tirs lors d'une séquence de tir;
• l'unité de programmation est munie de moyens pour la mémorisation de l'ensemble des temps de retard qui sont programmés dans les modules d'allumage. L'unité de commande de tir et l'unité de programmation sont aptes à dialoguer pour permettre le transfert, avant une séquence de tir, de l'ensemble des temps de retard programmés;
• les unités de commande de tir et de programmation sont munies de moyens de codage destinés à limiter leur accès à des personnes autorisées et de moyens pour leur reconnaissance mutuelle interne avant le transfert des temps de retard programmés de l'unité de programmation sur l'unité de commande de tir.

The coded assembly is advantageously supplemented by the following different characteristics taken alone or in all their technically possible combinations:

• each ignition module comprises a time base formed by an RC circuit;
• the programming unit is able to communicate separately with each ignition module, for memorizing the explosion delay times in said ignition modules and the fire control unit is able to transmit the firing phases during a shooting sequence;
• the programming unit is provided with means for memorizing all the delay times which are programmed in the ignition modules. The fire control unit and the programming unit are able to dialogue in order to allow the transfer, before a firing sequence, of all of the programmed delay times;
• the fire control and programming units are provided with coding means intended to limit their access to authorized persons and means for their internal mutual recognition before the transfer of the programmed delay times from the programming unit to the unit fire control.

Another object of the invention is still a detonator ignition module comprising a supply circuit, a communication interface, a pyrotechnic charge management circuit comprising in particular a tank capacity intended, after loading, to discharge into a detonator primer head, as well as a logical unit for managing the assembly.

According to the invention, this ignition module is characterized in that the pyrotechnic charge management circuit comprises, mounted in series with the tank capacity, a power source, for example the line voltage, a transistor for controlling the load of said tank capacity and a resistor connected by that of its terminals which is not directly connected to the capacity tank to a discharge switching transistor of said tank capacity to earth.

Given the environment in which these ignition modules are intended to be used, the simplicity of structure of the ignition modules proposed by the invention makes it possible to provide them with high reliability of use. In particular, the means of communication between the ignition modules of the invention and their firing line control unit are extremely simplified. Also, the ignition modules and detonators will be all identical and coded in production; they may only be individualized on site when programming the delay time.

These ignition modules are non-polarized. They can be used in large numbers, (200 or more) in parallel mounting, without this resulting in problems which could be due to a too large line current.

Yet another advantage of the invention is that the detonators of the firing assemblies are very safe to operate. The ignition modules are devoid of internal energy sources and do not present a risk of inadvertent ignition outside of the firing sequences. Procedures limiting access to the programming of the modules and to the control of the firing sequences are in particular provided, with in particular a coded pairing between on the one hand, the programming unit and the unit fire control, and secondly, the fire control assembly and the ignition modules.

Preferably, the impedance between the power supply of the pyrotechnic charge management circuit and the primer head is large enough so that the current generated by the line voltage in the primer head is, whatever the state of the control transistors, lower than the value of the non-operating limit current of said primer head.

Advantageously then, the discharge resistance of the reservoir capacitor is of a sufficiently large value so that the current generated by said supply in the primer head is whatever the state of the control transistors less than the value of the current limit of non-functioning of the primer head.

The description which follows is purely illustrative and not limiting. It must be read in conjunction with the appended drawings in which:

Figure 1 is a schematic representation of a detonator equipped with an integrated electronic delay ignition module according to an embodiment of the invention.

Figures 2A, 2B and 2C are schematic representations of a firing assembly comprising detonators mounted in parallel, of the type of those shown in Figure 1, showing the communication circuits established respectively during firing, during programming and when transferring programming information to the fire console.

Figure 3 is an overall representation of an ignition module according to the invention.

Figure 4 is a representation of the pyrotechnic charge management circuit of an ignition module according to the invention.

Figure 5 is a representation of the communication interface of the same ignition module.

Figure 6 is a representation of the supply circuit of the same ignition module.

Figure 7 is an illustration of the logic unit of the same ignition module.

Figure 8 is a schematic illustration of the communication principle, in a preferred embodiment. (during transmission (A) and during reception (B)).

The integrated electronic delay detonator shown in Figure 1 has a case 1 which serves as a housing and whose body 2 has an elongated cylindrical shape terminated at one end by a bottom 3. At its other end, this case 1 is closed by a plug also elongated 4, the walls of said case 1 being integral with said plug 4 by means of a crimping 5. The case 1 is made of aluminum alloy, the plug 4 being made of standard PVC.

The end 3 of the case is associated with an aluminum cover 6 comprising a bottom 7 arranged in a cross section of the case 1 and bordered by a cylindrical skirt 8 extending from said bottom 7 towards the bottom 3, the walls external of said skirt 8 substantially matching the internal walls of the case 1. The bottom 7 of this cover 6 is traversed in its thickness by a bore 9 whose outline is a circle centered on the axis of the case 1. This cover 6 defines with the bottom 3 and the walls of the body 2 of the case 1 a chamber 10 containing inside a charge 11, such as penthrite, this charge 11 being supplemented by a priming mixture 12 placed in said chamber 10 at the level of the cover 6. The proportions of penthrite and priming mixture are 0.6 g and 0.2 g respectively.

On the side of the cover 6 which is opposite to the chamber 10 is disposed a primer head 13 extending axially in the case 1 and protected by a cylindrical casing 14. This primer head 13 is directly connected to a integrated delay electronic ignition module 15 disposed in said case 1 between the casing 14 and the plug 4. This electronic module 15 is supplied, at its end, at the plug 4 by two sheathed wires 16a and 16b which pass through the plug 4 in its height and connect the module 15 to the ignition circuit.

A current of an intensity greater than the operating threshold intensity initiates the primer head 13, which through the cover 6 in the opening 9 excites the charge 12 and triggers the detonation.

Referring now to Figures 2A, 2B and 2C, it can be seen that the ignition modules 15 of the detonators are mounted in line in a parallel network with a fire control unit 17, also called a fire console. The firing unit also includes a programming unit or console 18. This is intended to allow, on the one hand, the programming of each module 15, before its installation in a hole, and in particular the storage in each module 15, the delay time allocated to it. On the other hand, the programming console 18 allows the memorization of the delay times programmed in the fire control unit 17.

Figure 2A shows the firing assembly in the connected state during a firing sequence. The fire control unit 17 is connected to the detonators, the programming console 18 then being inactive.

Figure 2B shows the firing assembly in a first connection state before a firing sequence. The programming unit 18 is connected to the ignition modules 15 for the unitary programming of the ignition modules in time delay.

Figure 2C shows the firing assembly in a second connection state before a firing sequence. This second connection state makes it possible, after having programmed the ignition modules 15 using the programming console 18, to transfer the programmed delay times to the fire control unit 17.

An ignition module 15, as shown diagrammatically in FIG. 3, comprises four subsystems: a pyrotechnic charge management circuit 300, a communication interface 301, a supply circuit 302, a logic unit 303 for managing the entire micro-system.

The pyrotechnic charge management circuit has been shown more particularly in FIG. 4. This circuit mainly comprises five N-channel MOS field effect transistors referenced in the diagram by 19, 20, 22, 23 and 192, and two transistors P-channel MOS field effect, referenced in the diagram by 21 and 191.

The transistor 19 is mounted as a common source, its source being directly connected to the ground. Its drain is connected, through a resistor 26, to a test circuit of a capacitor 29 which constitutes the reservoir capacity of the ignition module. Its grid is connected to a test line voltage.

The transistor 20 is mounted as a common source and is directly connected by its source to the ground. Its gate is connected to the logic management unit 303 of the detonator firing micro-system from which it receives the charge order for the capacitor 29. By its drain, the transistor 20 is connected to the gate of the transistor 21. A resistor 30 is mounted in derivation between the gate and the source of the transistor 21.

The transistor 21 is connected by its drain to a non-return diode 28, which is conducting for the currents passing through said transistor 21 to a resistor 27 of 12 kohms. The resistor 27 is mounted in series with the diode 28 and the transistor 21, these three components connecting a terminal of the primer head 13 to the line voltage L.

Resistor 27 and primer head 13 are also connected by their common terminal to one of the terminals of capacitor 29, the other terminal of which is connected to earth. This capacitor 29 has a capacity of 100 μF.

The transistor 22 realizes with a resistor 31 a discharge circuit without firing the reservoir capacitor 29. When the order to discharge the capacitor 29 is given to said transistor 22, this transistor 22 closes and puts the condenser 29 to earth by its two terminals. The capacitor 29 then discharges through the resistor 31.

The transistor 23 is connected by its drain to the other terminal, relative to that connected to the line voltage L, of the primer head 13. Its source is connected to the ground and its gate is connected to the unit logic 303 to be able to receive a firing control signal. A resistor 24 is connected in derivation between the gate of transistor 23 and the earth.

The transistor 20 only has the function of adjusting the voltage level between the outputs of the logic unit 303 for managing the microsystem and the commands of the other transistors. The charging of the reservoir capacitor 29 is controlled by the transistor 21, which is intended to put this capacitor 29 in connection with the line voltage L. The closing order is transmitted to the transistor 21 via the adaptation transistor of level 20.

The transistor 23 is the load firing member. When the firing order is transmitted to it, the transistor 23 closes and puts that of the terminals of the primer head 13 which is not connected to the capacitor 29 to earth. The capacitor 29 discharges in the primer head 13 and triggers the ignition.

A circuit 400 comprising a comparator 193, by means of which the voltage of the capacitor 29 can be quantified, ensures the connection of the management circuit with a microcontroller 45 of the logic unit 303.

The circuit shown in Figure 4 brings together all the necessary management elements of the firing process: the transistor 23 switches the pyrotechnic charge; the transistors 20 and 21 charge the firing capacitor 29; transistor 22 constitutes, with resistor 31, the discharge circuit of capacitor 29; and the transistors 19, 191 and 192 constitute a test circuit for the capacitor 29 and the primer head 13.

As soon as power is applied, the circuit is put in the following state: transistor 20 is open, this which means that the transistor 21 is also open and that the capacitor 29 cannot be charged. The transistor 22 is closed, so that any possible charge of the capacitor 29 is discharged. Transistors 19 and 191 are open, which causes the test circuit to be inhibited. The transistor 23 is open, so that no current can flow through the primer head 13.

In order for a current to possibly be considered dangerous and to ignite the primer head 13, the transistors 21 and 191 would have to be simultaneously closed, the transistor 22 being open and the transistor 23 being broken closed. This eventuality is highly unlikely. If it appeared, the primer head would be connected to the voltage line L through the transistor 21 and the resistor 27 of 12 kohms. Given the importance of the impedance made up of the primer head 13 and of the resistor 27, the maximum current passing through said primer head 13 would be of an intensity of the order of 2 milliamps, it that is to say much lower than the threshold intensity necessary for the operation of said primer head 13, or, in other words, much lower than the maximum non-operating current which is of the order of 130 milliamps. Thus, the resistor 27 has a double function in the pyrotechnic circuit: it limits the current when the capacitor 29 is charged; it protects the primer head 13 in the highly unlikely event of a simultaneous failure of the transistors 21, 22 and 23.

During the test, the transistor 19 charges the firing capacitor 29 with 100 µF at a voltage of 3 V. The energy related to the resistance the primer is then 0.16 mJ / ohm. This value is lower than the maximum non-operating energy which is 0.16 mJ for 5 µF. Thus, charging the shot capacitor during the test phase does not represent any danger.

By current injection, the test circuit is capable of detecting the presence of the primer head 13. This current is of the order of 1 mA, that is to say below the maximum intensity threshold of non-functioning, which is of the order of 130 mA.

The communication interface of an ignition module has been more particularly shown in FIG. 5. It comprises a receiver sub-assembly 32 and a transmitter sub-assembly 33. These two sub-assemblies 32 and 33 provide the bidirectional connection on the one hand with the firing console 17 and on the other hand with the programming console 18 when it is connected to said module 15.

The receiver sub-assembly 32 is intended to detect the polarity changes applied to the line by the shooting consoles 17 or programming consoles 18. It mainly comprises four N-channel field effect VMOS transistors, referenced at 341 to 344, mounted each with a common source, the source being connected directly to earth, as well as a P-channel field effect VMOS transistor, referenced at 345, mounted as a common drain, the drain being connected to earth through a resistor 374. The gate of transistor 341 is connected on the one hand to the logic unit 303 for managing the microsystem and on the other hand to a resistor 373 through which the gate is connected to earth. The drain of transistor 341 is connected on the one hand to the gate of transistor 342 and on the other hand through a resistor 371 connected to the module power supply described in more detail with reference to Figure 6.

The drain of transistor 342 is connected to a common terminal 361 to which are also connected a resistor 36, the drain of transistor 343 and the line. The common terminal 361 is connected through the resistor 36 to the operating voltage V _CC .

The gate of transistor 343 is connected on the one hand, through a resistor 372, to the power supply module and on the other hand to the drain of transistor 344. The gate of transistor 344 is connected on the one hand, through a resistor 374, to earth, and on the other hand to the drain of transistor 345. The source of transistor 345 is connected to the operating voltage V _CC and the gate of transistor 345 is connected to logic unit 303 for managing the microsystem.

The transistors 342 and 343 convert the switching of the line into pulses understandable by the logic unit 303, while the transistors 341 and 344 fix the quiescent state of the signal "line in". Since the receiver sub-assembly 32 is only sensitive to the polarity and not to the amplitude of the signals applied to its input, this sub-assembly is more tolerant of online loss phenomena.

The emitter sub-assembly 33 includes a VMOS N-channel field effect transistor, referenced at 38 and, two resistors referenced at 39 and 391. The transistor 38 is mounted at common source, the source being connected directly to earth. Its grid is connected on the one hand through the resistor 391, to the earth and on the other hand to the output line. The drain of the transistor 38 is connected, through the resistor 39 to the line voltage E. The resistor 39 of 470 ohm creates an over-consumption of current on the line E when a voltage pulse is supplied by the output line of the microcontroller to the gate of transistor 38.

The supply of an ignition module 15 is shown in Figure 6. This circuit is intended to provide a DC voltage of about 4 volts, including during the firing phase. This module essentially comprises a pair of Zener diodes 40, a rectifier bridge 41, a first voltage regulator 42, a second voltage regulator 43 and a capacitor 44 of 1000 μF.

The rectifier bridge 41 switches the voltage coming from the line and frees the ignition module from any polarization.

The first voltage regulator 42 guarantees a charging voltage of 12 volts at capacitor 44 for a line voltage comprised "in absolute value" between 12 volts and 30 volts.

The second voltage regulator 43 uses, to supply the rest of the system at 4 volts, the line voltage or the energy stored by the capacitor 44.

The logic unit 303 which manages each ignition module 15 is of the conventional type. It is shown in Figure 7.

The logic unit 303 manages the communications with the line, as well as the commands of the pyrotechnic charge. It comprises a microcontroller 45, including a program memory, as well as a "delay time" memory 47 which is chosen to be of the EEPROM type. The memorization of the delay time is therefore permanent, but can be erased and reprogrammed electrically at any time.

The microcontroller 45 technology allows consumption as low as possible, a speed of execution and a sufficient number of inputs and outputs.

In order to be in optimal industrial conditions (functional reliability in operating environment and manufacturing cost as low as possible) the time base is not controlled by a quartz but by a simple RC circuit, referenced in 48 and 49.

As the manufacturing tolerances for standard R and C components are ± 10%, the oscillation frequency of each pilot can vary by ± 20% compared to the precision required for the ignition module delay time.

If it is admitted that the time base, or the management clock of an ignition module, can be false by ± 30% compared to the typical value sought, we can guarantee delay times to an accuracy better than 0.5 millisecond. During the programming operation of each ignition module, its time base, which is false by construction, is precisely measured with respect to the quartz of the programming console.

The setting error of the management clock is measured and a corrective factor for adjustment to the precise value sought is deduced therefrom and applied to the ignition module to obtain the correct delay.

• une unité logique organisée autour d'un micro-contrôleur, par exemple du type de celui commercialisé par la société MOTOROLA sous la dénomination 68HC11, et qui intègre 512 octets de mémoires EEPROM permettant de stocker de manière non volatile certains paramètres de fonctionnement, tels que les retards des modules programmés, une mémoire vive RAM, un réseau d'entrées et sorties, une communication de type RS232 pour permettre aux consoles de tir 17 et de programmation 18 de dialoguer ensemble;
• un afficheur à cristaux liquides lumineux;
• une alimentation qui fournit une tension de ± 5 volts à l'unité logique, et de plus ou moins 10 volts à l'interface ligne, la tension amont nécessaire étant de 15 volts;
• une interface ligne constituée de deux sous-systèmes, dont une partie émission qui est une alimentation stabilisée pouvant commuter pour délivrer plus 12 ou plus 6 volts, et une partie réception qui mesure le courant consommé sur la ligne et qui détecte les surconsommations transitoires des modules d'allumage 15.

The shooting consoles 17 and the programming consoles 18 will now be described. They are similar structures and differ mainly in their functionality and therefore in the management software with which they are associated. Each console includes:

• a logic unit organized around a microcontroller, for example of the type marketed by MOTOROLA under the designation 68HC11, and which incorporates 512 bytes of EEPROM memories allowing non-volatile storage of certain operating parameters, such as delays of programmed modules, RAM memory, an input and output network, RS232 type communication for allow the shooting consoles 17 and programming 18 to dialogue together;
• a bright liquid crystal display;
• a power supply which supplies a voltage of ± 5 volts to the logic unit, and more or less 10 volts to the line interface, the necessary upstream voltage being 15 volts;
• a line interface consisting of two subsystems, including a transmission part which is a stabilized power supply which can switch to deliver more than 12 or more 6 volts, and a reception part which measures the current consumed on the line and which detects transient over-consumption of the modules ignition 15.

• programmation du temps de retard d'un module d'allumage 15;
• effacement de son écran;
• effacement du contenu de la mémoire de stockage de temps de retard d'un module d'allumage 15;
• test d'un module d'allumage;
• lecture du temps de retard d'un module d'allumage;
• transfert des temps de retard des modules d'allumage programmés vers la console de tir.

The programming console 18 includes a keyboard of 12 alphanumeric keys and a red indicator light and has six functions:

• programming the delay time of an ignition module 15;
• erasing his screen;
• erasing the content of the delay time storage memory of an ignition module 15;
• ignition module test;
• reading the delay time of an ignition module;
• transfer of the delay times from the programmed ignition modules to the firing console.

The implementation procedure is as follows: the operator programs the time on the keyboard desired delay in milliseconds. Delay times can range from 1 to 3000 milli-seconds. They are different for each ignition module and are used to identify them during dialogues between the ignition modules and the consoles. For artificers, a difference of 8 milli-seconds between two detonator delay times is not significant. It is therefore possible, if one wishes to detonate several detonators in a pyrotechnically synchronous manner, to assign them delay times offset from one another from milli-seconds to milli-seconds.

As a variant, each delay time can be completed by a programming order number. By this measure, it is possible to assign to several control modules the same delay time, while being able to address each control module individually.

The operator then validates the delay time by pressing the corresponding validation key. The console 18 then sends the programming order to the ignition module 15 and requests it to read the programmed delay time. If the information returned by the module corresponds to one millisecond near to that programmed, the screen of the console 18 displays that the programming is correct. Otherwise, the console 18 requests that programming be resumed.

The erase function is used if the operator has made a mistake in entering the delay time. After each programming of an ignition module 15, the delay time is stored in an EEPROM memory of the programming console 18. Once all the delay times programmed and memorized, these are transferred to the console of shot 17, automatically during the connection between the two consoles, by means of the RS232 type serial link, by a transfer function provided on the programming console 18. An internal self-test also makes it possible to test each ignition module 15. L return indication is global. A red light indicates any incorrect procedure or asking for confirmation.

The firing console 17 comprises three test / arm / firing keys, two green and red indicator lights for the test phase and a magnetic card suitable for the firing console; it has five functions: automatic transfer of data from the programming console 18; ignition module test 15; cancellation of the shooting; charging of the capacitor-tanks 29; shoot.

The implementation of a firing sequence is as follows. Once the ignition modules 15 have been programmed using the programming console 18, and as indicated above, the programmed delay times will be transferred from the storage EEPROM memories of said programming console 18 to the EEPROM storage memories of said firing console 17, after the introduction of the appropriate magnetic card or any other security device to the firing console authorizing connection with the programming console. Once the transfer has been made, the operator gives the firing console 17 an order to test the ignition modules 15 online.

Each ignition module 15 returns binary information on the line relating to its operating state: information of the "correct module" or "incorrect module" type, or possibly more complicated.

The pulses sent to the firing console 17 are returned for each ignition module 15 with a delay time corresponding to the delay time for which said module 15 has been programmed. On reception, the firing console 17 opens for each detonator a time window around the delay time programmed by the console 18 and which it has in memory. It is in the delay time with which the console 17 receives information which makes it possible to identify the module 15 from which it comes, this delay time corresponding to the firing delay time from which the module has been programmed. This therefore assumes that the transfer to the firing console of the delay times by the programming console has been carried out. This transfer of information from the ignition modules 15 online has been more particularly illustrated in FIGS. 8A and 8B, of which FIG. 8A shows the timing diagram in sending, and of which FIG. 8B shows the timing diagram in reception.

Upon receipt of the test order, the modules 15, referenced by M ₁ , M ₂ ... M _n , return to the firing console 17 one or more binary pulses corresponding to the information to be transmitted to the console. firing 17. The pulses are offset with respect to an identical zero time for each ignition module 15 by a time T ₁ , T ₂ , ..... T _m corresponding to the firing delay time, including the module M _m returning information has been programmed. The shooting console 17 will open as many windows F ₁ , F ₂ , F _m of time observation as there are ignition modules M _N. For a pulse lasting 250 micro-seconds, the time observation windows F ₁ , F ₂ , F _m opened by the firing console 17 may be of the order of 750 micro-seconds (250 micro-seconds before and after l 'impulse).

After this test, the operator gives, from the firing console 17, to the ignition modules 15, the charging order of the capacitors. A message validates the completion of this loading.

At any time the operator has the possibility of canceling the shot and giving the order to the ignition modules 15 to discharge their capacitor-reservoir. After loading, the console 17 awaits the firing order. After validation, the firing order is given to the different ignition modules.

One of the advantages of the ignition module which has just been described is that it does not include any energy source. It is therefore very reliable, since it presents no risk of inadvertent ignition of the pyrotechnic charge as long as the detonator with which said ignition module is associated is not mounted in line. The discharge of the capacitor 29 from an ignition module 15 will be controlled either directly by an operator from the firing console 17, or internally by the ignition module itself, after four seconds following the line wires cut after explosion of the first detonator.

Numerous security procedures are also planned. Access to shooting consoles and programming consoles will require the operator to be provided with recognition codes. The shooting and programming consoles, as well as the ignition modules can be customized before leaving the factory. Recognition may also be provided between the programming consoles and the shooting consoles. In the event of theft in particular, an operator will only be able to use a firing console if it corresponds to the programming console that was used to program the modules ignition 15. An recognition by an internal code of the programming console by the firing console will be provided for this purpose. If the code is not recognized, the shooting console will not record the information relating to the delay time stored in the programming console. The shot will be blocked.

In addition, the shooting console can be provided with a magnetic card authorizing its use.

It will also be noted that, although the assembly has been provided for on-site programming, factory programming, for people not wishing to program on site will also be possible.

In the circuits represented in the various figures, certain connection points are designated by signal names or indications of type of voltage. Points of the same name are then intended to be connected to each other.

The reference signs inserted after the technical characteristics mentioned in the claims, have the sole purpose of facilitating the understanding of the latter, and in no way limit their scope.

Claims (11)

1. Method of controlling detonators fitted with integrated delay electronic ignition modules (15), each encoded ignition module (15) comprising a reservoir capacitor (29) designed, after loading, to discharge in an ignitor (13) of its detonator in order to generate a firing electrical pulse, a time base as well as a logic unit (303) fitted with a memory in order to store in said ignition module (15) a delay time for the explosion of said detonators, during a firing sequence, said ignition modules being able to communicate with a firing control unit (17) designed to transmit them an order to load the reservoir capacitor (29) as well as a firing order and to receive from said modules, data about their conditions, method according to which, before a firing sequence, their delay time is stored in the ignition modules via a programming unit (18),
   characterized in that, once the ignition modules have been programmed, the delay times programmed are stored in the firing control unit (17) via the programming unit (18) and in that the firing control unit (17) interrogates simultaneously the ignition modules via an on-line test order, before the loading phase and the firing phase and in that the ignition modules send back to the firing control unit (17) global information about their condition, according to a time sequence corresponding to the firing time sequence.
2. Method according to claim 1, characterized in that during programming, the time base of every ignition module is measured.
3. Method according to claim 1, characterized in that the delay times are different for every module (15) and that the modules send the information requested back after a feedback time with respect to the delay time stored in each of them, said firing control unit (17) opening reception gate time corresponding to the feedback time.
4. Encoded firing control assembly comprising a firing control unit (17) and ignition modules (15) with integrated electronic delay for detonator, connected electrically on-line to said firing control unit (17), the line between the firing control unit (17) and the ignition modules (15) being used to supply said ignition modules, as well as for communications between said firing control unit (17) and said ignition modules (15), and a programming unit (18),
   characterized in that the ignition modules comprise means enabling them to send to the firing control unit (17) information in the form of overconsumption of the line current, whereas the firing control unit (17) is fitted with detection means of a line current overconsumption with respect to the average consumption of the ignition modules.
5. Encoded firing control assembly according to claim 4, characterized in that every ignition module comprises a time base formed by an RC circuit.
6. Assembly according to claim 4 or 5, characterized in that the programming unit (18) is able to communicate separately with every ignition module (15), to store the explosion delay times in said ignition modules, and in that the firing control unit (17) is able to monitor the firing phases during a firing sequence.
7. Assembly according to claim 6, characterized in that the programming unit (18) is fitted with means for storing of all the delay times which have been programmed and are transferred separately by the programming unit to every ignition module and in that the firing control unit (17) and the programming unit (18) are able to communicate in order to enable transfer, before a firing sequence, of all the delay times programmed.
8. Assembly according to anyone of claims 4 to 7, characterized in that the firing control (17) and programming (18) units are fitted with encoding means designed to limit their access to authorized people and with means for internal mutual recognition before transfer of the delay times programmed of the programming unit (18) to the control unit (17).
9. Detonator ignition module comprising a supply circuit, a communication interface, a management circuit of the pyrotechnic charge comprising a reservoir capacitor (29) designed, after loading, to discharge in an ignitor (13) of a detonator, as well as a logic unit (303) for the management of the assembly, characterized in that the management circuit of the pyrotechnic charge comprises, mounted in series with the reservoir capacitor (29), a supply source, for instance line voltage, a switching transistor (21) for the control (17) of the charge of said reservoir capacitor (29) and a resistor (27) linked by the one pin which is not connected directly to the reservoir capacitor (29) to a switching transistor (22) to discharge said reservoir capacitor (29) to the ground.
10. Module according to claim 9, characterized in that the impedance between the supply of the management circuit of the pyrotechnic charge and the ignitor (13) is high enough so that the current generated by the line voltage in the ignitor (13) is, whatever the condition of the control transistors, less than the value of the operating limit current of said ignitor (13).
11. Module according to claim 10, characterized in that the discharging resistor (27) of the reservoir capacitor is high enough so that the current generated by said supply in the ignitor (13) is, whatever the condition of the control transistors, less than the value of the operating limit current of said ignitor.

Images