DE102015005707A1 - Modular IR high performance seeker - Google Patents

Abstract

The invention relates to an infrared seeker head for a guided missile, comprising an outer spherical shell segment (1) containing an optical dome, and an inner hollow sphere (2) in which the full interior space for the camera (s) is available via one on the surface of the hollow sphere (2) slidably mounted nipples (4) driven by a simple commercially available XY slide, pivotable in use up to +/- 90 ° in half space, and pivotable beyond 90 ° for camera image homogenization.

Description

Abbreviations:

• IR

  = infrared

  SK

  = Seeker

  FOV

  = field of view = field of view

  FOR

  = fiels of regard = swing angle

  FK

  = Missile

  IR SK

  = passive infrared seeker

  SAL

  = Semi-active laser seeker (such as in the HELLFIRE-FK)

  line of sight

  = Direction of the camera = center of the FOV

  HELLFIRE

  = well-known American missile

  Camera consisting of camera optics 5 and detector 7 and optional deflection mirror 6

Conditions:

The seeker SK is located at the front end of a guided missile. A camera in the seeker head must be pivotable in the pitch and yaw directions. Bottom view seekers typically require the 25 ° -35 ° pivot angle FOR in the azimuth (= yaw angle) and elevation (= pitch angle) and rarely more than 1 ° field of view size FOV. However, due to the greater agility, both the targets and thus the missile, up to about 90 ° yaw and pitch pivot range (= half-space) are required against flight targets. A camera, usually an IR camera, with a small field of view (provides long range), so it must be possible up to 90 ° in the pitch and yaw direction swivel. Both the pitch and yaw deflections must be exactly around the center of the SK dome. Only then is the optical effect of the dome the same for all directions of view and thus the image sharpness for all viewing directions can be guaranteed. Therefore, the optics possibly existing other cameras (= dual-mode SK) with z. B. other visual field sizes or spectral ranges concentric and not juxtaposed. The optical dome must thus represent a spherical shell cutout and serves for the aerodynamic and weather protection of the SK. However, a spherical shape is aerodynamically unfavorable; u. a. Therefore, the dome diameter should of course be as small as possible.

He stood technic

The pivoting is usually realized by suspending the camera in gimbal. For relatively simple solutions, the possible swivel angle range FOR is limited to approximately +/- 35 °. Quite complex solutions such as In DE 101 53 094 Although offer around the 90 ° swivel angle, but at the price, the optics high-precision with intermediate images on the axes of rotation of the gimbal must have to lead. The effort is much greater than with smaller swivel angle ranges. Therefore, so far seekers against ground targets and against air targets are each completely different developments. In DE 103 13 136 z. B. the gimbals outside, but also here the gimbals need space (and weight) in the quite limited (front) space of a missile. And specially shaped magnetic drives are complex in development and production. And the swivel range is still at max. 70 ° limited. In DE 10 2004 008 644 only partially 90 ° swivel angle possible with elaborate Aussenkardanrahmen. In any case, angle gauges called resolvers are necessary to the gimbal, which allow to accurately measure the direction of the gimbal relative to the missile and thus to determine the sighting direction of the camera. The gimbal axles must pass exactly through the center of the dome. The gimbals (including payload) must also be precisely balanced, which greatly limits the freedom in the design of the cameras, to avoid that vibrations in the missile lead to angular movements of the line of sight. The camera sits in the inner gimbal. The cable guide to the camera in order to Power and signal feedback must pass through the gimbals in the missile. In one of the gimbals, a gyroscope is attached as a bearing reference.

Description of the invention:

There are no more gimbals. And thus eliminates the above-mentioned boundary conditions with respect to the gimbal. The hollow sphere 2 is freely rotatable in the spherical shell segment 1 , Dom for short, stored. There are no (rotary) axes. This frees space and weight for a more powerful camera (larger opaques for longer range) or the SK can be made smaller, with the advantage of getting a more aerodynamic and lighter missile. There is also room for a dual mode SK (eg IR and SAL) available.

The pan of the camera is realized as follows:
(Schematic diagram, more detailed representation s. 1 )

The cathedral 1 consists at least in the central area of IR-transparent material in the edge region, it may be made of cheaper solid material. The dome is slightly larger than a hemisphere, hence the SK ball 2 is kept freely rotatable therein. Via nipple 4 , attached to the ball 2 or on the X / Y drive, then there is a hole in the hollow ball, the SK ball can be moved by an XY drive in the pitch and yaw direction. The panning is done automatically, as needed, exactly around the center of the dome. Approximately +/- 30 ° swivel angle (= usual demand for ground target applications) can be easily reached in the pitch and yaw direction. The cable routing from the SK ball into the missile FK is either through the then hollow nipple 4 or realized by a passage (hole) in the SK ball. The Nick-yaw drive, also called XY drive, is in 4 shown in more detail.

For a SK against ground targets you have a surprisingly simple solution, which also, as desired, leaves the entire space in the SK-ball for the camera. There are also no types of gimbal or bearings around the SK ball 2 necessary, which would then reduce the allowed SK ball diameter for a given FK diameter. With a digital XY drive, the sighting direction is known exactly and you do not need any measuring equipment to determine the sighting direction. This gives the possibility to implement a much more powerful SK => high-performance SK as it has not previously been possible in a given FK diameter. The dome is tight and tightly connected to the FK structure. Of course, no gimbal means weight, complexity and cost savings. When the dome is composed of 2 materials, the hollow ball is inserted before dome assembly. Otherwise, the hollow sphere must 2 consist of at least 2 parts and are joined together in the cathedral. The spherical shell segment 1 (Dom) can in the field of camera optics (including swivel range) also just have a hole, then you save expensive IR-transparent materials (a 180 mm diameter dome costs alone in material value around 4000 €, weighs about 800 gr 2 kg target weight for a total SK), but you must then between the Restdom 1 and the hollow sphere 2 insert a gasket against rain and moisture.

In addition, the solution is after 1 if required, easily extendable even for larger swivel angles. So you do not have to develop a completely new SK for applications against flight targets, the known SK of this type are highly complex, but simply extend the existing SK modular to about +/- 90 ° yaw and pitch tilt angle.

It saves separate SK developments separately for SK against ground targets or air targets.

Extension of the swivel angle (FOR) to approx. 90 °:

First of all, the swivel range of the XY drive is expanded to slightly more than 45 ° in the yaw and pitch directions. If necessary, the XY drive is extended to this larger route. Even larger swing angles would be possible on this way, but so are not achievable so 90 °. Therefore, a new solution had to be found here. It is easy to see that attaching the nipple 4 causes an offset of the directional range of the line of sight at another point of the hollow ball surface. If the nipple z. B. is 45 ° offset in the pitch direction on the hollow sphere upwards, and is positioned again in the middle of the XY drive, then the sighting line is directed in the pitch direction with 45 ° offset upwards, including maximum Y-drive deflection so 90th °. The drive nipple 4 So it has to be on the SK hollow sphere 2 be slidably mounted. In 5 is shown that the nipple 4 in the slot 12 can be moved. The easiest way to move the nipple is to use the existing XY drive, here only the Y drive. The nipple 4 can be locked, locked or released on the surface of the sphere, electromagnetically or mechanically. If the nipple 4 is released, it moves by means of y-drive in Schlötz on the ball surface (up to a little over 45 °). When the nipple is locked, the whole ball is turned as described above. If necessary, while driving the nipple in the slot, the hollow ball 2 be locked electromagnetically or mechanically. Next to the nipple 4 can also be an electrical cable 13 be moved together with the nipple in the slot. Thus, a simple cable management in the SK is possible. (S. 5 ). If the nipple 4 alternatively, as in 3b shown hollow and flexible in the passage through the hollow ball wall, the cable guide can also through the nipple 4 respectively.

Due to the 2-stage pitching motion,> 45 ° by Y-drive and additionally up to> 45 ° by displacement of the nipple 4 ,> +/- 90 ° pitch angle deflection is achieved (and so far about +/- 45 ° yaw angle). That is sometimes enough. If the sighting line fourteen to swing over the full half space in yaw and pitch direction, then another element must be added for this purpose. The hollow sphere 2 must now be open at the rear, in the opposite direction to the line of sight by a slightly more than +/- 45 ° cone angle.

In 6 is a handle 15 called element (because it looks like the handle of a bucket and so around the axis 16 is rotatable) added. However, there is a longitudinal slot in the handle, in which the nipple 4 can be shifted slightly over +/- 45 ° and then arrested at any desired location. The handle 15 can around axis 16 rotated slightly over +/- 45 ° and then locked in any position. The locking of the handle 15 happens by fixing in the axis 16 or through a tab 17 which are perpendicular to the handle 16 attached to the hollow sphere 2 ranges and there is mechanically or magnetically locked. The displacement of the nipple 4 on the hollow sphere surface happens, as already described above, by moving the XY drive and the ball 2 respectively the handle, is arrested for this time. In short: the nipple 4 can be moved in a cone area of> +/- 45 ° on the spherical surface and then locked. With the additional displacement by the XY drive surprisingly easy,> +/- 90 ° swivel range (half space) can be achieved and there is, even up to 90 ° swivel angle, a simple cable management.

Further description:

On the surface of the ball 2 Slippery knobs can move in the dome 1 facilitate said outer spherical shell segment and vibration damping effect. nipple 4 can also be fastened vibration resistant. The optics 5 may be shaped according to optical requirements, but may not be from the contour of the sphere 2 protrude.

The optional deflection mirror 6 allows long focal lengths (=> long ranges) and fexiblen structure of the optics and easy balancing and can then be used for fine stabilization of the sighting line by means of conventional commercially available piezo stabilization.

Through a hollow nipple 4 The cables can be routed from the camera to the missile, easily in the entire half-space swivel range.

The moment of inertia of the SK, (important for damping of vibrations), by the masses as far as possible outside the balls, optimally large.

It should also be mentioned that no singularity in the Visierlinienansteuerung such. In DE 298 24 923 occurs. (Before you can pan from yaw in nick direction, or vice versa, the entire SK has to be rolled 90 ° there).

Camera Bildhomogenisierung

Infrared cameras resolve temperature differences of about 20 mK at about 300 K scenario temperature. Since all image pixels must have extremely exactly the same sensitivity (and noise). This can only be achieved by an electronic adjustment of all pixels. Typically, this is done by looking at a homogeneously tempered surface and then correcting all pixels to the same signal level and noise level and storing the correction values for each pixel in a look-up table; 2-3 pictures (ie <100 msec) are enough for the Einichung. This process is no problem during production. In a search head (in the battlefield), after perhaps 10 years of storage and then use in the desert or in the Arctic, the correction values must be updated, otherwise the camera image shows a fix pattern noise. Since it is of great advantage to be able to look at a homogeneously tempered Fache (and not in the battlefield) just before use with the camera. This is achieved by ball 2 with the camera in it, is pivoted in one direction beyond 90 °. Realization by the slot in the handle 15 extended beyond 90 ° and by means of XY drive ball 2 rotated in 2 steps over 90 °.

Again, the main advantages of the invention:

• - Simplest design of the SK and therefore cheap in development and production Commercial X-Y drive is sufficient. With digital drive you know exactly the deflection of the sight line, you do not need to measure the direction.
• - No (disturbing) gimbal => It remains for the camera (s) much more space than with all other previously known SK => higher performance (range)
• - or: the SK can be built smaller and therefore more aerodynamic
• - Swivel angle of the camera can be reached up to about 90 °. Easy cable routing, even for large swivel angle, through the nipple 4 ,
• - No singularity in the drive.
• - Updated image homogenization of the camera in flight by swiveling to the side easily possible.
• - One SK development for all applications vs. ground and flight targets.
• - Saving the optical dome is optional.

LIST OF REFERENCE NUMBERS

1

Spherical shell segment, at least in the central region transparent in the spectral range of the SK camera, = short named cathedral

2

SK hollow sphere with the camera in it, camera consisting of 5 and 7 and optional 6

3

FK structure

4

Nipple with 8th

5

camera optics

6

deflecting

7

Detector = CCD chip of the camera

8th

joint

9

X-Y frame

10

Y-rail

11

X-rail

12

Slot in the shell of the hollow sphere

13

Cable (runs from the camera to the FK)

14

Sighting direction (of the camera)

15

handle

16

Axle for handle 15

17

Latch on Henkel 15 (Optional)

18

Slit in handle 15

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10153094 [0002]
• DE 10313136 [0002]
• DE 102004008644 [0002]
• DE 29824923 [0016]

Claims (1)

A seeker head on the front end of a guided missile, consisting of an inner hollow sphere 2 , optionally with recesses, with at least one camera therein, and an opening in the hollow sphere shell 2 in which the optics of the camera is located, and an outer spherical shell segment 1 , which is transparent in the field of camera optics, including Schwenkberreich, for the spectral range of the camera, and which supports the inner spherical shell, freely rotatable, characterized in that: 1. on the inner hollow sphere 2 attached to its surface, a nipple 4 sits, by means of which a conventional known linear XY slide by its displacement, the inner hollow ball and thus the sighting direction of the camera, in yaw and pitch direction by up to slightly over +/- 45 ° pivots. 2. The nipple 4 is displaceable on the hollow ball surface and is magnetically or mechanically locked in any new position. 3. The displacement of the drive nipple 4 in the unlocked state by means of XY slide on the hollow ball surface in yaw and pitch direction and then can be locked at each sliding location. 4. A handle 15 with slot 18 the nipple 4 in a cone of about 45 ° on the hollow sphere 2 can position. 5. The inner hollow sphere can also be swiveled in one direction over 90 °, so that the camera optics does not look into the landscape, but rather at a homogeneously tempered surface in the seeker head.

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