DE102011016907A1 - Infrared seeker for guided missile, has front lens integrated in spherical shell and dimensioned such that front lens does not project above outer contour of shell, where spherical shell is held in missile flight direction by retaining ring - Google Patents

Abstract

The seeker has a camera (13) firmly built into a spherical shell (3). The shell is outwardly held in a missile flight direction by a circular missile-fixed mechanical retaining ring (4), where diameter of the ring is larger than diameter of a front lens of an optical system (6) of the camera and smaller than diameter of the shell. The front lens is integrated in the shell and dimensioned such that the front lens does not project above an outer contour of the shell. Vibration-absorbing and easily sliding materials are arranged between the ring and the shell and function as pane wiping rubbers.

Description

Technical area

It's about an infrared seeker for guided missiles. The seeker head is located in the tip of the missile and can be pivoted relative to the missile longitudinal axis in azimuth and elevation (= squint angle).

State of the art:

In all known IR seekers, the IR camera is pivotally suspended in the seeker head. This is necessary because the camera field to achieve high ranges can only be small (at most a few degrees) and the squint angle to the missile axis usually greater +/- 25 ° (total> 50 °) when used against ground targets and still much larger when used against Air targets (squint angle up to +/- 90 ° in half space) must be. Usually, the camera is suspended in yaw and pitch gimbals. The camera can therefore be horizontally (yaw) and vertically (nod) pivoted by means of the gimbal. So there are two gimbals in each other necessary. The gimbals take up much space in the limited missile diameter. Only a limited amount of space remains available for the camera. The camera must be arranged in the gimbal extremely precisely balanced, otherwise the required visual stabilization in flight can not be achieved. The possible swivel angle (equal to squint angle) are quite limited.

In 5 is a conventional infrared seeker head with pitch and yaw gimbal seen. You can see immediately that the space for the camera is severely restricted by the gimbals. In 6 is from the patent DE 10 2007 002 an exemplary seeker optics with detectors (= camera) taken. Such a camera is usually in gimbal like in 5 seen in the patent but omitted, arranged. In front of the optics and the gimbal, an optical dome is necessary for protection and sealing against the environment. The dome must have spherical shape, otherwise the optical properties would change when panning the camera. And so it is also necessary that the camera is pivoted exactly around the center of the dome. This center of rotation is not at larger focal lengths (= lengths and ranges), as necessary, in the focus of the camera incl. Suspension. And the pan range of the camera is limited to typically +/- 25 °. This swivel range is usually sufficient for ground targets. That's why most seekers are so realized. If larger swivel angles are required, the optics must be guided over several gimbal frames. For this purpose, intermediate images must be realized in the optical beam path (2 gimbals 2 pieces) and in the axes of rotation of the gimbal mirrors (or prisms) are arranged over the beam path runs. The effort is so significant and the space for the camera and the optics design is still smaller. A schematic diagram of such an arrangement can, for. B. from the cover sheet of DE 101 53 094 be removed. The detector pixel sizes are now in the micron range, z. B. usually at 2 microns. The beam guidance over the gimbal must be correspondingly precise. It may z. B. in the military temperature range of typ. -40 ° C to + 70 ° C no play (<< 2 microns) in the gimbal. The focus of the optics must then be kept over the gimbal in the temperature range.

Description of the invention:

There is a hollow ball or at least a ball cutout, here called a ball shell (s. 1 ). The camera is compactly built into the spherical shell. The front lens of the optics is integrated into the ball cup and is part of the ball cup. The front lens is dimensioned so that it does not exceed the outer contour of the ball socket. The beam path can be deflected within the spherical shell via a mirror in order to be able to realize longer focal lengths (= longer ranges). The deflecting mirror can then preferably also be formed immediately as a commercially available piezoelectric mirror for stabilization. The limited space in the missile for the camera is not limited by gimbals. The camera can be bigger and therefore more powerful (more range). The camera can be built stiff and compact in the spherical shell. An optical dome is not required, but can be added. The spherical shell is completely free to rotate about its center, held in a missile-resistant retaining ring in the direction of flight forward (s. 1 .) And by the pressure of the friction wheel or a second retaining ring opposite the first retaining ring.

Here will now be described how the ball socket, according to claim 2, with the camera is actually rotated in all directions.

There is a friction wheel which rests firmly on the outer shell of the spherical shell (s. 1 ). The outer skin of the spherical shell is roughened. The friction wheel is driven by a motor. Upon rotation of the friction wheel, the ball shell rotates. The friction wheel is rotated by means of the second motor about an axis through the center of the spherical shell in each case so that the desired direction of rotation of the spherical shell is achieved. engine 2 So determines in which direction the spherical shell moves with the camera in it will and engine 1 determines by what angle the ball cup is rotated. engine 2 sits on an axis that goes through the center M of the ball cup.

The camera can be moved freely in all directions in the half space. Only when the line of sight is deflected is the optics slightly vignetted (shadowed) by the retaining ring with the retaining bars. There are at z. B. 80 mm optics diameter and 5 mm retaining ring width at most 7% intensity lost. This is far less than in the prior art lost by many lenses and deflecting mirrors or prisms. The camera consists of the optics, the deflection / stabilization mirror and the detector (in Dewar).

Additional lenses may be inserted, if necessary, for correction between the front lens and the detector.

A dome is not necessary, but can be added to protect it if desired.

When the detector image plane is tilted in the dewar (as in 1 sketched), one can accommodate the detector / dewar unit more easily in the spherical shell.

Between retaining ring and ball socket vibration-damping elements (Socking Mounts) can be attached. This reduces the vibration load on the camera and facilitates visual line stabilization.

Between retaining ring and ball socket and a windshield wiper and washing device can be installed. The wiping is done by moving the ball cup. A frost-resistant detergent can be sprayed onto the optics by means of fine nozzles from thin tubes guided along the retaining ring.

If the missile rolls around its longitudinal axis (a rare requirement), the seeker can also be unrolled if needed.

Electricity and data transmission.

For all applications with squint angles around 25 ° to 30 ° in azimuth and elevation, (ground target applications) can be a wiring harness 17 for power supply and data transmission are guided directly through the ball socket in the missile as in 4b drawn.

In elevation or azimuth 90 ° deflection can be achieved with the cable. Often a large swing angle in one direction and 25 ° -30 ° in the other direction is sufficient.

But if really 90 ° in azimuth and elevation are necessary, the current is inductively across the opposing coils 15a and 15b (S. 4a ) transfer. The sink 15b is mechanically attached to the missile structure. The inner coil 15a becomes magnetically opposite from coil 15b held. In principle, data can also be transmitted inductively.

A high data transmission rate is known to be achieved via an optical fiber. According to the invention, the inner optical fiber becomes the coil 15a guided and mechanically fastened there. Through the transparent wall of the ball shell, the light runs to the coil 15b attached outer optical fiber.

Advantages of the invention:

The camera can look out in the entire half space (+/- 90 °). The camera is completely in the ball socket and not on different gimbals.

There are no gimbal frames that would otherwise severely restrict the available space for the camera and limit the range to typ. +/- 25 ° and require precise balancing. The stabilization mirror takes over the high-frequency stabilization of the camera images. The motors need only perform the relatively low-frequency rotation of the camera in the desired direction.

A motor drives the desired pivoting direction by rotating the friction wheel in the desired direction and the second motor controls the size of the pivoting angle. Commercially available motors can be used.

Of course, if you can get a large squint angle, then you can use such a seeker head even for applications with smaller squint angles. One no longer needs to develop completely different seekers for different applications. Being able to use a seeker head, which can be adapted for all applications, is of course also a great advantage.

In short: There is about 3 × more room for the camera and large viewing angles up to 90 ° in a modular universal search head.

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 102007002 [0003]
• DE 10153094 [0003]

Claims (9)

Seeker head for guided missiles with a camera permanently installed in a freely rotatable in all directions about its center spherical shell characterized in that: the spherical shell in the missile flight direction outside through a circular missile-resistant mechanical retaining ring whose diameter is greater than the respective front lens diameter and smaller than the ball shell diameter and a An abutment is held and in the ball shell, at least the front lens of the optics of the camera is integrated, wherein the front lens of the optics is dimensioned so that it does not dominate the outer contour of the spherical shell. The ball socket with the camera inside is rotated in each direction by a driven friction wheel. By a motor ( 2 ) on an axis which passes through the center M of the spherical shell, the direction of rotation of the ball socket is adjusted and by a second motor ( 1 ) is adjusted by rotation of the friction wheel, the size of the deflection. Between retaining ring and ball socket vibration damping and easily sliding materials are arranged. The materials between the retaining ring and spherical shell also work as windscreen wiper rubbers for the optics. In addition to the retaining ring, but mechanically connected to the retaining ring thin tubes with nozzles for the application of cleaning or anti-freeze solutions are mounted on the optics Between the optics and the detector, a deflection and stabilizing mirror is arranged. The detector image plane is arranged inclined to the dewar longitudinal axis. The power supply of the camera in the spherical shell inductively via coils, one half of which is held magnetically opposite to the other half, takes place. The data transfer from the camera in the spherical shell in the missile via an optical fiber whose inner part is fixed in the spherical shell to the inner magnetically held coil and whose outer part is attached to the outer coil so that the light through the transparent spherical shell wall from the inner optical fiber can enter the outer optical fiber.

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