Weapon system

Abstract: A weapon system including a primary weapon (2) arranged to be guided to a target, and further comprising at least one secondary weapon (5) forming a unit with the primary weapon, but being releasable from the primary weapon on the approach to a target, the secondary weapon or weapons being controllable, on release, to ensure target destruction should the primary weapon not succeed in target destruction.

Description: This invention relates to guided weapon systems. Hitherto guided weapons have been guided towards a target and have either impacted with it or detonated near it to cause destruction. However, if for what ever reason neither action results in destruction the mission has failed and a further weapon or wave of weapons must be launched at great expense and doubtful efficiency. Moreover any delay in such launch will lessen the likelihood of a kill success. The present invention therefore has for an objective the provision of a weapon system which can effect destruction of a target even if the prime weapon does not do so. It in effect, provides a belt and braces arrangement. EP-A1-114901 discloses a submissile carrier and particular mechanisms for the release of submissiles from the carrier. US-A-4770101 discloses an unguided submunition warhead containing several deployable flechettes. DE-A1-2364195 discloses a multiple-warhead weapon system which requires a ground-based telemetry station for measuring distances between weapon and target. The system holds the multiple warhead on its trajectory until it is highly likely to hit the target, in which case the warheads are activated together. In cases where a direct hit cannot be expected, then the secondary warheads are ejected to continue along their own trajectories. According to the present invention there is provided a weapon system including a primary weapon arranged to be guided towards a target and containing at least one secondary weapon and being provided with means for releasing said secondary weapon thereform, characterised in that said primary weapon is further provided with sensor means for detecting target miss-distance and transmitter means for transmitting data generated by said sensor to said secondary weapon, and in that said secondary weapon is provided with receiving means for receiving said data transmitted from said primary weapon and with means for altering course in response to said received data thereby to impact said target. Preferably the control on release of the or each secondary weapon includes not only course correction but retardation with respect to the primary vehicle. Preferably the or each secondary weapon are housed with the primary weapon prior to release. Reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a cross-sectional diagram of the front part of a weapon system according to a first and second embodiment of the present invention and shows the deployment of submunition by leaf spring. Figure 2 is a cross-section diagram of the rear part of a weapon system according to a third embodiment of the present invention, and Figure 3 and 4 are diagrams for illustrating the functioning of the embodiments of the invention, whereby Fig.3 shows the course correction by submunitions and Fig.4 shows the assessment of path-pass by carrier-vehicle. In Figure 1 a weapon unit shown generally at 1 includes a primary weapon 2 and a number of secondary weapons (of which 2 are shown) 5 which are held in a circumferential recess 6 in the primary weapon body. As a consequence the section 7 of the body is of smaller diameter than the rest of the primary weapon body. Springs 8 (for example leaf springs) are located between section 7 and secondary weapons 5. During normal flight of the primary weapon the springs are held compressed by covers 9 which encase recess 6, and press the secondary weapons towards section 7 of the primary weapon body. At a predetermined time during the flight of the weapon, the covers 9 are removed, in any known way, and the secondary weapons are deployed from of the recess, so that they remain substantially parallel to the axis of the primary weapon. This could be achieved by aerodynamic means alone or as is mentioned above by a pre-set mechanism, such as a spring. The spring has the advantage, that due to the fact that the side impulse is pre-set, the secondary weapons will fly a path parallel to that of the primary weapon, but offset by a known amount. The secondary weapons are designed to have a greater relative aerodynamic drag than the primary weapon. As a result the secondary weapons start to lag behind as flight of the primary weapon continues. The primary weapon may be guided towards a target by a suitable homing device, however in the first embodiment of the invention it is anticipated that course correction will be complete by the time the secondary weapons are deployed, i.e. there is no subsequent manoeuvring of the primary weapon. In the second embodiment the secondary weapons may be slaved to the primary weapon so that the primary weapon can be manoeuvred after separation and the secondary weapons follow. This would be the preferred embodiment since separation could occur earlier than in the non- slaved embodiment thereby making timing of the separation less critical. Another preference for the slaving embodiment is that manoeuvring of the primary weapon can be continued up to a shorter range. In either of the above mentioned embodiments, at a certain point the primary weapon should be 'on target' and about to impact the target. If the primary weapon does impact the target the aims of the mission will be achieved and no further action will be taken. However, if the primary weapon for some reason or another misses the target further action is taken. The primary weapon is equipped with a sensor 12 (as shown in Figure 4) which views the target 13 as it passes, and measures the relative geometry in terms of "miss-distance" in 2-dimensions and "time of interception" as the third. The sensor could be common with those used to home, but are much more likely to be specifically designed for the purposes described. The sensor will operate only as the primary weapon passes the target and may use time-dependent signal processing techniques. The sensor will then calculate any required course correction to ensure the secondary weapons 5 (as shown in Figure 3) impact the target. A signal command broadcast 14 is then transmitted to the secondary weapons so that they may effect any required course correction, for example at a predetermined point, say 20. This course correction may be achieved in any known manner, for example by means of a circumferentially placed thruster unit. The position in roll of each secondary weapon being referenced to ensure correct course correction. The time lag between the primary and secondary weapons is sufficiently large to allow for the calculation time and the reaction times of the two weapons of the system. The offset between the primary and secondary weapons may be compensated in the course-correction command. Each secondary weapon may calculate its own correction based on a common, broadcast command from the primary weapon. In Figure 2 the third embodiment of the invention is shown. In this case the secondary weapons 5 are located in the rear section 30 of the primary weapon 31. At the appropriate time the secondary weapons slide out of the back of the primary weapon via ports 32. The initiation of the deployment may be activated by springs (not shown) as in the previous embodiments, or merely by gravity as a result of say the flight path of the primary weapon being somewhat upwards, or in any other way, for example, by virtue of the greater relative aerodynamic drag of the secondary weapons. It should be noted that the secondary weapon may be located anywhere within the primary weapon. For example the secondary weapons may be deployed from inside the primary weapon one at a time so that they are not offset from the carrier as is shown in Figure 3. The secondary weapons may alternatively be attached to the outside of the primary weapon or towed behind the primary weapon. Any number of secondary weapons may be deployed from a single primary weapon the number being dependant upon space and weight consideration. The leaf spring may be replaced by a number of springs of any different type. The deployment of the secondary weapons can be effected at anytime during the flight but at the latest will probably be about half a second from interception.

Claims: A weapon system including a primary weapon (2) arranged to be guided towards a target (13) and containing at least one secondary weapon (5) and being provided with means (8) for releasing said secondary weapon therefrom, characterised in that said primary weapon (2) is further provided with sensor means (12) for detecting target miss-distance and transmitter means for transmitting data (14) generated by said sensor to said secondary weapon (5) and in that said secondary weapon (5) is provided with receiving means for receiving said data transmitted from said primary weapon (2) and with means for altering course in response to said received data thereby to impact said target. A weapon system according to Claim 1 in which said secondary weapons (5) are stowed in a circumferential recess (6) in said primary weapon (2) and in which the means for releasing said secondary from said primary weapon comprise leaf springs (8). A weapon system according to Claim 1 in which said secondary weapons (5) are stowed in rear section (30) of said primary weapon. A weapon system according to any preceding claim in which the aerodynamic drag on said secondary weapon (5) is greater than that on said primary weapon (2). A weapon system according to any preceding claim in which the means for altering course of said secondary weapon is a thruster unit.

Inventors: BALL RICHARD FRANCIS, BALL, RICHARD FRANCIS
Applicants: BRITISH AEROSPACE, BRITISH AEROSPACE PUBLIC LIMITED COMPANY
Application year: 1990
Main classification: F41G7
IPC codes: F41G7, F42B12