GB2207987A - Target sensor for munitions - Google Patents

Description

1 A SENSOR FOR A MUNITION 2r n 1 ' 0- --- 2U/58i This invention relates to

sensors, for target detection, for seeker fuze munitions, and munitions incorporating such sensors.

Sensors are known for instance, from DE-OS 33 23 519 and from DE-OS 33 26 876, which serve for the acquisition of specific target objects by picking up reflections or characteristic radiations from a target area, and for the evaluation thereof to effect genuine-target detection, in order to initiate, upon selection of a target object to be combatted, homing-in on the target and/or detonation of a charge. In this respect, the invention is particularly relevent to sensors of the aforedescribed type for seeker-fuze munitions, which sensors are arranged rigidly with respect to the munitions-technology effective direction or axis (for instance the direction of the firing of a projectile-forming charge).

The problem underlying the invention is to provide simple to produce, easy to handle and operationally reliable means for aligning a sensor effective axis with respect to a predetermined system or reference axis, which predetermined axis may be the effective axis of another sensorP cooperating in the course of the signal processing with the aforementioned sensor, or of the munition- technology effective axis or direction. It has been found that, through a fine adjustment of the effective axis relative to the predetermined axis, the probability of a hit on a target by a munition equipped with such sensors can be perceptibly improved beyond normal expectation. In general therefore, the invention provides means to permit delicately sensitive or fine variation of the setting of the sensor effective axis, and preferably also to permit stable locking of the 2 adjusted setting, in view of the stresses which can occur, for instance, upon the firing of a munition, equipped with such a sensor, f rom a barrel weapon or a carrier projectile.

More particularly there is provided a sensor for target detection, for a seeker-fuze munition, comprising at least one sensor part, having a sensing direction., supported by a holder f ixed relative to a predetermined axis, and an adjustment mechanism interposed between said sensor part and holder, the mechanism comprising relatively arcuately movable parts which abut in an inclined plane of separation inclined to an axis, and which are mutually rotatable for adjustment of the sensing direction relative to the predetermined axis.

In an embodiment of this sensor, the adjustment mechanism enables the effective axis of the sensor to be swivelled relative to the predetermined axis, e.g. munition- technology effective or reference axis, so that a portion of the sensor remains fixed relative to the predetermined axis whilst said one sensor part is swung by means of that mechanism relative to the fixed portion and thus the predetermined axis. The swingable part can be a radiation optical system (or a part thereof) of an infra-red sensor the detector elements of which are arranged in a system- fast manner; or the swingable part may be an antenna (or an antenna reflector or a part of the antenna reflectors) of a millimetre-wave sensor, the wave guide of which is arranged in a fixed manner relative to the predetermined axis. If a munition is equipped with several sensors, an adjustment mechanism can be provided for each sensor, in order not only to be able to preset an offset or inclination relative to the munition effective axis, but also to be able to set between the sensors slightly but definedly different m 3 ef f ective directions or axes in order to provide a lead or respective leads necessary (by reason of the kinematic factors of the munition system with respect to the target object that is to be acquired) to give time for processing of the information obtained from the target surroundings by means of the different sensors, as well as for triggering and distance traversing of the warhead effective part, after detection of a genuine target.

Irrespective of whether by means of the adjustment mechanism, a sensor part as previously mentioned, or the sensor as a whole, is swivelled or swung with respect to the predetermined reference axis in order to achieve the desired mutual effective-direction displacement, the desired direction can be set in either case by rotating one of the two parts of the adjustment mechanism relative to the other.

On the one hand, a mechanism providing for only such relative movement may not permit totally independent adjustment of the sensor effective direction or axis relative to two orthogonal axes, but this independent two-axis adjustment is something which, however, in practice is not strictly necessary, because setting or adjustment has to be carried out only once as a final adjustment. On the other hand, there emerges with such a mechanism an extremely space-saving and mechanically extremely stressable structure, because the two parts of the mechanism, in the direction of the predetermined system axis (and thus in the direction of an acceleration stress), in any inclined position of their abutting surfaces, rest on one another in a relatively large-area manner along the oblique separating plane and can be axially mutually supportive in the final angular position.

4 Preferably, at least one of the arcuately movable parts has an axis concentric to or parallel with the predetermined axis, and preferably the adjustment mechanism is of ring form, surrounds a part of the sensor, and is divided along the inclined plane of 5 separation.

The arcuately movable parts preferably have slots which extend arcuately concentrically to the axes of the arcuately movable parts, and into which slots there 10 engage guide bolts or pins which are held or are securable in positions fixed relative to the holder; and the bolts preferably serve as clamping fasteners to clamp the arcuately movable parts and prevent relative movement thereof.

The adjustment mechanism is preferably arcuately movable relative to the holder and engages the holder in a plane normal to said predetermined axis; and may be arcuately movable relative to said one sensor part.

The invention includes and further provides a munition incorporating the sensor in accordance with the invention.

The whole adjustment mechanism is preferably arcuately movable relative to a fixed part of the munition.

Additional alternative and further developments, as well as further features and advantages, of the invention will become apparent from the general description in the abstract and from the following description of a preferred example of the invention which is shown approximately true to scale in the accompanying diagrammatic simplified drawings, wherein:FIGURE 1 shows in axial longitudinal section a millimetre-wave sensor in reference-coaxial alignment; and FIGURE 2 shows, in a representation which is enlarged 5 compared with FIGURE 1, the sensor adjustment mechanism in accordance with FIGURE 1.

In this exemplified embodiment the sensor 11 is an active (Radar) or passive (radiometer) millimetre-wave sensor, of a Cassegrain type of construction, which has a - wave guide 12 aligned at a convex sub-reflector 13.8. The sub-reflector is positioned by means of a reflector holder 14 approximately at the focal point of a concave main reflector 13.9 of greater radial extent. A hollow- cylindrical sensor holder 15 defines a predetermined reference axis 16.1 of the system of sensor installation in a munition. In the present example, the wave guide 12 is mounted rigidly coaxially with this reference axis 16.1. The high-frequency and evaluation circuits of the sensor are situated to the rear of the sensor holder 15 and are connected to the wave guide 12, and these and other functional devices, such as a hollow-charge warhead, behind the holder 15, are not shown in the drawings.

1 The sensor 11 is orientated ahead in the effective direction 17; i.e., it picks up radiation energy contrary to this direction 17 in order to be able to derive therefrom specific information (such as regarding the surroundings lying ahead or the instantaneous detection of the target object sought) and, for example, to be able to evaluate such information for generating an item of detonation information.

Depending on the collaboration with further 6 mechanisms aligned coaxially or axial ly-paral lel to the system reference axis (16.l.)- (such as with further sensors or respectively with a direction-orientating warhead), specific relatively small effective-axis differential angels can be set relative to the effective -direction 17, or respectively the reference axis 16.1, so that, for example, sensors of other functional units, arranged in axially-parallel or near parallel manner in the effective direction 17 ahead according to the trigonometrical factors, cover, scan or detect the same point, or respectively so that sufficient function-buffer or lead periods (for instance for the signal processing of for the distance traversing by a launched projectile) between consecutive covering, scanning or detecting at or of the same point by f irst of all one unit such as the sensor 11 and af ter that other units are ensured. For adjustment of such differential angles, means is provided for shifting the respective effective axis 16.2 relative to the reference axis 16.1, by swinging or swivelling of the effective axis 16.2 about at least two axes orthogonal to one another in a plane transverse to the axis 16.1. If, in the case of a unit such as the sensor 11 in accordance with FIGURE 1, the wave guide 12 is arranged rigidly in the reference axis 16.1, the swivelling of the effective axis 16.2 is effected by appropriate swivelling of at least one of the reflectors 13. In the exemplified instance shown, the edges 18 of the frusto-conical sub-reflector holder 14 and of the dish-shaped main reflector 13.9 are connected directly together, so that the swivelling of the effective axis 16.2 is effected by swivelling of the entire reflector arrangement 13 relative to the sensor holder 15.

For this alignment adjustment, arranged between the adjustable sensor part (thus here the reflector arrangement 13) and the sensor holder 15 is a multi-part, 7 in this exemplified embodiment two-part, adjustment mechanism 19. It consists of a reference part 19.1 facing the sensor holder 15 and an effective part 19.2 arranged in the effective direction in front thereof, which are rotatable relative to one another along a common separating plane 20 which extends approximately transversely to the axes 16, but is inclined so as not to extend at a right angle to either the reference axis 16.1 or the effective axis 16.2. In the positioning shown in FIGURE 1 and FIGURE 2, a reference surface 21.1 (securable to the sensor holder 15) extends parallel to the oppositely- lying effective surface 21.1 carrying the reflector edges 18, so that in this position of the swivel mechanism 19 the effective axis 16.2 coincides with the reference axis 16.1, and the effective direction 17 is thus aligned coaxially with the system axis. if now the one swivel part 19.2 is rotated relative to the other swivel part 19.1 along the separating plane 20, there emerges from this geometry a lateral angular deflection of the direction of the effective axis 16.2 to one side away from the original common axis 16; and if also the other swivel part is rotated about the reference axis 16.1, the effective axis 16.2 describes the generatrix of a conical surface with the position of the cone tip at the point of intersection 22 of the axes 16 through the inclined separating plane 20. The maximum deflection, or respectively cone-angle, and thus the delicate sensitivity of the adjustment possibility, is thus determined by the inclination of the separating plane 20 relative to the reference axis 16.1. On account of the slight inclination of the separating plane (which is less than the angle of repose of the materials of which the parts 19.1 and 19.2 are made) the setting becomes fixed by self-locking of the parts 19 when they are clamped together.

8 The two parts of the mechanism 19 do not, as shown, have to be hollowcylindrical, thus annular in design. At any rate in the case of this shaping it is, however, expedient, as taken into account in FIGURE 2, to fashion in the outer wall surfaces 23 supporting formations 24 (such as recesses or projections), for engagement by hooked wrenches, hook spanners or other tools, (not shown in the drawings), for the mutual rotation of the swivel parts 19.1 and 19.2. A rotation guidance is effected advantageously by means of guide members such as pins or bolts which are held in axially-parallel manner in the sensor holder 15 and which engage through guide slots 26, extending in concentric-circular- arc-shaped manner, in the swivel parts 19.1 and 19.2. The arcuate length of these slots 26 then determines thus the possible angle of rotation between the parts 19.1/19.2 and thus the maximum deflection of the effective axis 16.2 relative to the reference axis 16.1.

If the guide members are screws or bolts having heads 27, they can, besides this guidance functions, then serve for the securing of the swivel parts 19. 1/19. 2 in their adjusted relative positions to the holder 15, thus fixing the setting of the effective axis 16.2 relative to the reference axis 16.1. In order, upon this axial securing, not to damage or deform the peripheral edge portion 18 of the reflectors 13 or respectively of their holder 14, the headed screws 27 preferably act, as shown, upon and are tightened down onto an underlaid supporting ring 28 which overlies said edge portions 18 to clamp them onto the adjustment mechanism.

z 9

Claims (12)

1. A sensor for target detection, for a seeker-fuze munition, comprising at least one sensor part, having a sensing direction, supported by a holder fixed relative to. a predetermined axis, and an adjustment mechanism interposed between said sensor part and said holder, the mechanism comprising relatively arcuately movable parts which abut in an inclined plane of separation inclined to said predetermined axis, and which are mutually rotatable for adjustment of the sensing direction relative to the predetermined axis.

2. A sensor as claimed in Claim 1, wherein one of the arcuately movable parts has an axis concentric to or parallel with the predetermined axis.

3. A sensor as claimed in Claim 1 or 2, wherein the adjustment mechanism is of ring form and surrounds a part of the sensor, and is divided along the inclined plane of separation.

4. A sensor as claimed in any one of the preceding claims, wherein peripheral surfaces of the arcuately movable parts are provided with supporting elements or formations for engagement by an adjusting tool or tools.

5. A sensor as claimed in any one of the preceding claims, wherein the arcuately movable parts have slots which extend arcuately concentrically to the axes of the arcuately movable parts, and into which slots there engage guide bolts or pins which are held or are securable in positions fixed relative to the holder.

6. A sensor as claimed in Claim 5, wherein the bolts serve as clamping fasteners to clamp the arcuately movable parts and prevent relative movement thereof.

7. A sensor as claimed in any one of the preceding claims, comprising a fixed millimetre-wave guide, and wherein said one sensor part comprises a reflector arrangement which is held by the adjustment mechanism, so as to be movable relative to the wave guide.

8. A sensor as claimed in any one of claims 1 to 6, comprising a fixed optronic or infra-red detector and wherein said one sensor part comprises a radiation optical system which is held by the adjustment mechanism so as to be movable relative to the detector.

9. A sensor as claimed in any preceding claim wherein the adjustment mechanism is arcuately movable relative to the holder and engages the holder in a plane normal to said predetermined axis.

10. A sensor as claimed in Claim 9 wherein the angle between the plane normal to the predetermined axis and said plane of separation is less than the angle of repose for the materials of which the arcuately movable parts are made.

11. A sensor substantially as hereinbefore described with reference to the accompanying drawings.

12. A munition incorporating a sensor as claimed in any preceding claim.

Published 1986 at The Patent Office. State House. 6671 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. D87- Qi