ES2279074T3 - ELECTROPIROTECHNICAL SAFETY DEVICE FOR AMMUNITION AND CONTROL METHOD. - Google Patents

Abstract

Procedure for controlling at least one electropyrotechnical safety device (2) coupled to a trip system (1), this device being able to communicate with the firing system (1) to send a current (I) to transport information (M) of control of at least one function of this device and an energy drive for the ignition of a device (3) of said device, a procedure that consists in not authorizing the passage of said energy drive to said device (3) more than when it gives at least one authorization to circulate this drive through said firing system (1), this procedure consisting in: a) generating in said firing system (1) said control information in the form of a message (M) composed of the less a logical word (m1, m2, m3 ...) representative of said circulation authorization function; b) transmit said logical word to the electropirotechnical safety device (2); c) analyzing said logical word enéste to extract from it a control signal of said circulation authorization function, and d) giving the circulation authorization to said electropyrotechnical safety device (2) in response to said control signal, this procedure being characterized because said circulation authorization function is duplicated in said electropyrotechnical safety device (2) and because it consists in executing operations a), b) and c) for each of said functions and not giving the authorization to circulate the current flow ( I) to said device (3) more in response to the accumulated appearance of the two control signals produced.

Description

Electropyrotechnical safety device for Ammunition and control method.

The present invention relates to a control procedure of an electropirotechnical device of security for ammunition, intended to be coupled to a system of shooting, as well as with an initiator for such a device safety electropirotechnic.

In the context of the present invention, understands by electropirotechnical safety device a device formed by an artifice such as a bait, a detonator, an inflamer or analog and a payload, which can be very various natures, such as a pyrotechnic ignition composition, ejection and / or propulsion, a set of decoy cartridges or also a dynamite cartridge used, for example, in the field of civil engineering. At the time of use, these electropirotechnical safety devices are coupled to a firing system that can also be of very conceptions diverse.

In the case of the lure especially, such electropyrotechnical safety device can be part of a multi-cartridge ammunition fixed on the structure of an aircraft, each of these cartridges being provided with a artifice. The cartridges are fired successively under the control of a firing system that provides ammunition with cartridge selection signals, control signals necessary for its firing and the electrical energy necessary for its start and for the operation of your electrical equipment.

To ensure the safety of people and of the goods, it is necessary to make the ignition of a device electropyrotechnics cannot take place except if certain predetermined conditions according to severe criteria. This applies naturally both for military applications and for civil engineering applications.

EP 0.798.535 describes a system of transmission of information between a weapon (that is, a system of firing) and an ammunition by which the conditions of gun safety with the help of safety switches, which they are inserted in an electric circuit of the weapon, ensuring the ammunition feed, and on which they are transmitted bidirectionally control and verification signals exchanged between the electronics of the weapon and that of the ammunition. In In this case, the main safety function that determines whether or not to turn on the device in the system Shooting

This has the disadvantage that a Ammunition not coupled to the firing system can be fired by application of the necessary energy without having to go through the safety function Thus, a hostile entity that has to be abandon ammunition, or in the case of civil use, non-competent or ill-intentioned people can fire the ammunition sending the ignition current to the device necessary.

From document DE 100 04 582, a procedure of the type defined in the preamble of the claim 1.

In this case, the firing system releases a message representing a circulation authorization function of a drive of energy for the ignition of the device, message which is transmitted to the pyrotechnic safety device in the which is analyzed to extract a control signal from it authorization function The circulation authorization is then released to the pyrotechnic safety device in response to This control signal. Therefore, by this procedure the operation of the device cannot be possible except when authorization is given for this purpose on the device itself safety electropirotechnic. The security of the function is thus secured as close to the place where this will be fulfilled function.

The object of the invention is to propose a control procedure of an electropirotechnical device whose safety conditions are even better with respect to secured in the prior art.

The invention therefore has as its object a procedure that presents the characteristics defined in the characterizing part of claim 1.

Thanks to these characteristics, it is necessary, therefore, the accumulated appearance of two control signals so that can transmit the authorization to release the device. Be it becomes thus impossible an untimely or fraudulent ignition when the ammunition is separated from the firing system. It results from it a greater overall security of the whole system shot-ammunition.

Other advantageous features of the method of the invention in subclaims 2 to 11.

The object of the invention is also a electropyrotechnical safety device coupled to a system tripping as defined in claim 12, being precise advantageous features of this device in the claims 13 and 14.

Other features and advantages of this invention will appear in the course of the description provided then given by way of example only and made referring to the attached drawings, in which:

- Figure 1 is a simplified scheme of a electropyrotechnical safety device according to the invention;

- Figure 2 shows an example of a form possible message that can be exchanged between a system of shooting and an electropyrotechnical safety device according to the invention connected to this firing system;

- Figure 3 shows an example of a form possible of the words that make up the message in figure 2;

- Figure 4 shows a message according to the Figure 2 in which an ignition drive of the electropyrotechnical safety device.

In Figure 1, block 1 represents a trigger system designed to form M messages (figures 2 and 4) and to direct these messages to an electropirotechnical device of security 2 according to the invention (represented below by the abbreviation DEP). This DEP is incorporated into an ammo that has not Been represented in detail. The DEP includes an artifice pyrotechnic 3 intended to cause the operation of the ammunition. DEP 2 is also capable of directing messages back to the system trigger 1.

In the example shown, the system of trip 1 is connected to DEP 2 by means of a union of two threads 4 on which messages that include the energy drive necessary for the operation of the device 3 and the information that is indispensable for its control. This two-wire connection 4 is connected to the DEP 2 by only two terminals 5 and 6, no other outward connection is provided for the DEP 2.

It should be noted that, according to variants of realization, communication between trigger system 1 and the DEP 2 can be established by other means. For example, the energy of on and control information can be transmitted by inductive, optical or analogous route, then providing elements of appropriate coupling for this purpose between the firing system 1 and the DEP 2.

The communication pathway (in this case, the union two-wire 4 and terminals 5 and 6) is connected to a block of emission / reception 7 which constitutes an interface capable of deriving incoming and outgoing messages, respectively, towards internal functional blocks of the DEP 2 and, as the case may be, towards the firing system 1.

Incoming messages appear on a line 8 which is connected to a power supply block 9 and a microcontroller 10.

The feed block 9 is designed to generate the supply voltage U on a terminal 11. The latter is connected to power terminals 12 of all other blocks of the DEP 2.

The microcontroller 10 is also attached to the transmission / reception block 7 via a line 13 on the which messages pass before leaving DEP 2.

The pyrotechnic device 3 is linked between terminals 5 and 6 respectively by means of controlled switches 14 and 15 that form a series circuit with artifice 3. By consequently, the initiator 3 cannot be turned on except if the Two switches 14 and 15 are closed. Each of the switches 14 and 15 can be closed by a circuit of drive 16, respectively 17, which in turn receives signals of control of the microcontroller 10. Switches 14 and 15 are preferably made in the form of controlled semiconductors as transistors or analogs. At least two can be foreseen switches and at least two control signals.

The microcontroller 10 also controls a circuit called "sterilization" 18, as well as a circuit called "destruction" 19. The sterilization circuit 18 is connected to drive circuits 16 and 17, to which can render inoperative in order to prevent the operation of switches 14 and 15.

The destruction circuit is connected not only to drive circuits 16 and 17, but also to emission / reception block 7. When the microcontroller 10 sends a control signal, this destruction circuit 19 allows destroy the blocks to which it is attached and thus prevent all communication from abroad with the electronics of the DEP by middle of terminals 5 and 6.

As is known per se especially by the aforementioned European patent, the power circuit 9 includes a 9th energy storage capacitor that, when charged, allows the DEP 2 circuits to be temporarily fed, that is, at least for the time that it is needed to ensure the firing of the ammunition to which the DEP is incorporated.

For this purpose, the firing system 1 is ready to generate M messages (figure 2) that include information encoded in a series of words m_ {1}, m_ {2}, m_ {3} ... formed themselves by a series of bits. At example described here, the topology of a message M is preferably of the UART type known to specialists, which it has eight bits framed by a start bit and a bit of ending; the information flow can be selected at 9,600 baud, for example. In the case described, and as represented in figure 3, each word m_ {1}, m_ {2}, m_ {3} ... of message M is therefore composed of bits B_ {start}, B_ {0} to B_ {7} and B_ {end}.

       \ newpage
    

At least the first word m_ {1} of each M message sent to the DEP 2 is intended for loading the capacitor 9a of the power circuit 9. Preferably, the content of this word is that of the example in figure 3, given which allows to transfer a maximum of energy to the circuit of feed 9 (code "55" in hexadecimal based on a octet).

Table 1 below lists, by way of example, the functional content that words can have compose a message M, such as the one presented in figure 2. It should be noted that these words can be followed in an order desired by the conceptor to perform a sequence of events default in DEP 2, it being understood that, depending on the capacitor capacity 9a of the power circuit 9, It is convenient to insert, or between two functional words Consecutive defining functionality (calls below "function words"), or between several of these words, a word called "feed" whose logical composition it is then the one represented in figure 3.

The second column of table 1 represents the sense of circulation of information, which is directed at the system Trigger 1 to DEP 2 for all words, except for word 8, which implies an inverse circulation of the information.

       \ vskip1.000000 \ baselineskip
    

one

       \ vskip1.000000 \ baselineskip
    

As already mentioned above, the word of No. 1 power codes for circuit power of DEP 2. This code (figure 3) is preferably "55" in hexadecimal to allow the transmission of a maximum of energy for this word. For example, if the intensity of the current I sent by trigger system 1 to DEP 2 is 0.1 A, it is possible to transmit 50 µJ per word No. 1. In this case, if the electronic circuits of the DEP 2 consume a total current of 10 µA, its autonomy can be a maximum of 5 seconds with a capacitor 9a of adapted capacity. However, it can be admitted a shorter autonomy duration, for example 0.5 seconds only, which will reduce the size of the capacitor 9a. It should be noted in this regard that you can contemplate connecting to the capacitor 9a a load resistance 9b that absorbs the accumulated energy in the condenser if, during a period default (for a second, for example), has not transited no information from trigger system 1 to DEP 2. This energy absorption function ensures a safety of major operation of the DEP, leaving the electronics systematically in total wakefulness due to lack of food if the trigger system 1 does not activate it.

Function words No. 2 to No. 6 do not need particular comments, unless they are sent by the system trigger 1, its logical content is sent to microcontroller 10, that analyzes it and prepares the appropriate control and then sends a control signal to the corresponding organ or circuit of the DEP 2. For example, if word No. 2 is sent, microcontroller 10 activates drive circuit 16, which closes the switch 14. The same process is executed for all other words, it being understood that each of these words is preceded by the Word No. 1 that allows the capacitor 9a to be charged.

It will be noted regarding the activation of the artifice 3 that needs the cumulative closing of the switches 14 and 15, this action having the effect of authorizing circulation of a current in this artifice. It looks, then, that this authorization depends on elements that are located in the DEP, that is, of elements that are located as close as possible to the artifice. This feature especially provides the advantage of allow, when ammunition is separated from firing system 1, make ignition of artifice 3 impossible, making it impossible to untimely or fraudulent ignition without knowledge of the code that you should receive the microcontroller 10. As explained below, security in this regard can still be reinforced if the messages destined for microcontroller 10 suffer encryption to enable the execution of the functions they contain.

Word No. 9 contains the control of DEP sterilization by means of the sterilization circuit 18. This functionality then prevents the closing of switches 14 and 15, so that artifice 3 can no longer be ignited. Without However, DEP 2 can still respond to words No. 7 and 10 while they are sent by the firing system 1.

The word No. 10 has the effect of activation of the destruction circuit 19. Through this control, not only no switches 14 and 15 can be closed, but also the transmission / reception circuit 7 being destroyed, it can no longer take place no communication with the outside. This feature can be useful if the ammunition equipped with the DEP according to the invention it must necessarily be abandoned, for example, being then unable a hostile or unauthorized entity to shoot the ammo

Table 2 below shows as an example a possible coding of function word No. 7 of demand for status, each code corresponding to a status claim particular emitted by the firing system 1 towards the DEP 2. The demand claims a response from the DEP in the form of the Word No. 8, whose content is representative of a state determined from the DEP.

It should be noted that the word No. 8 is coded in particular, since, emanating from DEP 2, it is convenient that your shipment to the firing system 1 does not impose on the DEP 2 more than a very low energy consumption. This word No. 8 it is therefore coded preferably over a bit only, being able to take the value "1" or "0".

The code of function word No. 7 is preferably formed by an identification part over four bits that designate the state request, followed by a part also of a length of four bits that designate the nature of the status requested from the DEP. Table 2 lists the meaning of this Part of the requested status.

       \ vskip1.000000 \ baselineskip
    

       \ vskip1.000000 \ baselineskip
    

       \ vskip1.000000 \ baselineskip
    

(Table goes to page next)

2

As an example, assuming that the system shot 1 must successively check the status of the switches 14 and 15 and that of artifice 3, the message addressed by Trigger system 1 to DEP 2 will be as follows: Word No. 1 (table 1), word No. 7 (table 1) with code No. 4 (table 2), message No. 8 (bit "1" if the switches are closed and the bit "0" if the switches are open), word No. 1, the word No. 7, but with code No. 8, word No. 1, the word No. 8 (with bit "1" or "0" depending on the status of the artifice 3) and finally the code word No. 1.

According to a characteristic that favors particularly the operational safety of the DEP according to the invention, at least certain function words can be provided of at least one encrypted word in which the corresponding functionality control code.

As function word No. 7, each of the other function words in table 1 are composed of one octet whose four bits of greater weight identify the functionality correspondent. According to the invention, the four low weight bits of these words can define the length of a message from encryption, which can be sent in message M to continuation of a function word from table 1 that defines the functionality considered.

An encrypted message can be prepared in the trigger system 1 and be sent by groups of eight bits successive, each time with the interposition of the word of No. 1 power to charge the capacitor 9a. Encryption it can be performed in a known way with the help of an algorithm of public or private key encryption. In this case, the microcontroller 10 can run an decryption program corresponding loaded into your memory with the help of an algorithm reverse using the same public or private key as appropriate. The four low weight bits of each function word can thus define the length of the encrypted message, that is, its number of bits or, more precisely and preferably, quartets (group four bits).

It should be noted that, when the four bits low weight of the function word represent the value hexadecimal "0", the control code set is contained in the only octet of this word and there is no then encryption For example, if the function is to close the switch 14 and this function is considered as not very sensitive in the security plane, the sequence of words sent by the Trigger system 1 to DEP 2 will be as follows: Word No. 1, Word No. 2 (with the four low weight bits at "0", word No. 1 ...

The following word sequence illustrates as an example the control with encryption of the function of switch 15 closure, assuming the four bits of lower Function word weight have the value "8" (hexadecimal), which means that encryption is performed about eight quartets or 32 bits: word No. 1, word No. 3 with the code 8 (in hexadecimal), word No. 1, word No. 3 bearing the first encrypted quartet of lower weight, word No. 1, word No. 3 with the second encrypted quartet, word No. 1, word No. 3 with the third encrypted quartet, word No. 1, word No. 3 with the fourth encrypted quartet, word No. 1 ...

It should be noted that the security level of the transmission of messages between trigger system 1 and the DEP 2 will be the higher the higher the number of bits Encrypted Well understood, the treatment time will increase also with an increasing number of encrypted bits.

Thus, it may be advantageous not to encrypt on a important number of bits more than sensitive controls, such as, for example, the simultaneous closing functions of the switches 14 and 15, and select for the other functions bit numbers less high encrypted. One of the important advantages of the invention lies in the large selection of the degrees of confidence of which has the conceptor to conceive secured messages.

Function word No. 11 in table 1 is not used more than to start ammunition in manufacturing. May be advantageously used to determine the number of bits that You have to encrypt for each function word used.

Figure 4 illustrates a firing sequence that by way of example it implies a sequence of four words of function, of a period of sending the power on for the artifice 3 (time T) in the course of which current I rises to a comparatively very high level with respect to intensity used for the transmission of M messages, and finally several supplementary words sent after shooting to interrogate to DEP 2 regarding its status.

Claims (14)

1. Procedure to control at least one electropyrotechnical safety device (2) coupled to a firing system (1), this device being able to communicate with the trigger system (1) to send a current (I) to convey control information (M) of at least one function of this device and a power drive for the ignition of a artifice (3) of said device, a procedure consisting of not authorize the passage of said energy drive to said device (3) more than when there is at least one authorization to circulate this drive through said firing system (1), this procedure consisting of:

to)

generate in said firing system (1) said control information in the form of a composite message (M) for at least one logical word (m_ {1}, m_ {2}, m_ {3} ...) representative of said authorization function of circulation;

b)

transmit that logical word to electropyrotechnical safety device (2);

C)

analyze that logical word in this one to extract from it a control signal of said function of circulation authorization, and

d)

give the authorization to circulate to said device safety electropyrotechnic (2) in response to said signal of control,

this procedure being characterized by duplicating said circulation authorization function in said electropyrotechnical safety device (2) and for consisting of executing operations a), b) and c) for each of these functions and not giving the authorization of circulation of the current impulse (I) to said device (3) more in response to the cumulative appearance of the two signals of control produced. 2. Control procedure according to claim 1 of an electropirotechnical safety device (2) that includes electronic means of analysis and control (10, 16 to 19) and electric accumulation power supplies (9) to which is selectively sent the current (I) to ensure the power supply of said electronic means of analysis and control (10, 16 to 19), said procedure being further characterized as consisting, at least prior to the execution of said operations a), b) and c) in generating in said firing system (1) a Logic word feed and in accumulating the energy represented by the bits successive of this logical feed word in said means of accumulation feed (9) to allow the operation of said means of analysis and control (10, 16 to 19). 3. Control method according to claim 2, characterized in that the maximum logic word represents a maximum of possible transitions, such as the code "55" in hexadecimal, based on an octet. 4. Control method according to any one of claims 1 to 3, characterized in that it consists in generating in said firing system (1) at minus another logical word representative of another function that has been to comply with the electropyrotechnical safety device (2), in transmitting said other logical word to said electropyrotechnical safety device (2), in analyzing said logical word in said electropyrotechnical safety device (2) to generate a control signal of said other function and in executing said other function in response to said control signal that corresponds to it. 5. Control method according to claim 4, characterized in that said other function is capable of sterilizing said current circulation authorization function. 6. Control method according to any one of claims 4 and 5, characterized in that said other function is capable of controlling the destruction of at least a part of said electropyrotechnical safety device (2). 7. Control method according to any one of claims 1 to 6, characterized in that it also consists of generate in said firing system (1) a Functional logic word representative of a state demand for said electropyrotechnical safety device (2), transmit said function word to said electropyrotechnical safety device, generate in said electropyrotechnical device of security (2) a response to said state demand depending on of a certain state of this electropyrotechnical device of security and forward said response to said system of shot (1). 8. Control method according to claim 7, characterized in that said response is coded to a state request on a single bit. 9. Control method according to any one of claims 1 to 8, characterized in that it consists of encrypt at least part of that message (M) in said firing system (1) and decrypt said message portion in said electropyrotechnical safety device (2) before running said function defined in said message. 10. Control method according to claim 9, characterized in that at least certain logical words of function of said message (M) include a first group of bits encoding a predetermined functionality of said electropyrotechnical safety device (2) and a second group of bits that define the number of bits on which said message is encrypted and for being said bits of logical word encryption following the word of corresponding function. 11. Control method according to any one of claims 2 to 10, characterized in that, in said message, each logical function word is preceded and followed by logical supply words. 12. Electropyrotechnical safety device for ammunition coupled to a firing system consisting of:

an artifice (3) for the ignition of said ammunition;

means of sending / receiving (7) to receive from said firing system (1) a current (I) intended to convey control information (M) of at least one function of the electropirotechnical device of safety and a power drive for the ignition of a artifice (3) of the electropirotechnical device of security;

means of analysis and control (10, 16 to 19) to analyze the messages received and extract from them control signals;

this electropirotechnical safety device being characterized by said device (3) being connected to a current circulation circuit in which at least two switches (14, 15) are inserted that cannot be closed except in response to the accumulated production of at At least two predetermined control signals for the authorization of circulation of said energy drive in said device.

13. Electropyrotechnical safety device according to claim 12, characterized in that it also includes means (18) for sterilizing said switch (14, 15) in response to the production of another of said control signals. 14. Electropyrotechnical safety device according to any one of claims 12 and 13, characterized in that it also includes means (19) for destroying at least a part of said electropyrotechnical safety device (2) in response to the production of another of said signal signals. control.