GB2112955A

GB2112955A - Missile directing sights with protective hood

Info

Publication number: GB2112955A
Application number: GB08234547A
Authority: GB
Inventors: Brian Thomas Trayner
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1981-12-05
Filing date: 1982-12-03
Publication date: 1983-07-27
Also published as: GB2112955B

Abstract

Missile directing apparatus for mounting upon a helicopter, for example, including a movable optical sight 1, 4 within the field of view of which a missile must be positioned in flight, a gathering tracker 7, a movable protective hood 5 with a window 6 covering the sight, and slave means 10-12 for ensuring that as the sight is moved the hood is moved such that the line of sight always passes through the window, the arrangement being characterised in that the gathering tracker 7 is carried by the hood 5 and that overriding means 13 are provided so that the slave means can be overridden to direct the gathering tracker 7 independently of the sight to a position in which the missile can be gathered rapidly on launch and can subsequently be directed into the field of view of the optical sight. <IMAGE>

Description

SPECIFICATION Missile directing apparatus This invention relates generally to missile directing apparatus of the type having movable sighting means within the field of view of which a missile must be in flight in order to be directed onto a target.

Because when a missile is launched it does not necessarily enter the field of view of the sighting means a further sighting means, conveniently known as gathering tracker, is often used to track the launched missile so that it can be guided into said field of view. Furthermore, the movable sighting means may have a protective hood in order to avoid detrimental enviromental effects.

Such a hood includes a window of limited area and it is therefore arranged to be movable; it is slaved to the movable sighting means so that the line of sight of the latter always passes through the window and is not restricted by the hood.

The present invention specifically relates to missile directing apparatus including these features; it has for an objective to provide relatively simple missile gathering in such apparatus.

According to one aspect of the invention, missile directing apparatus includes movable sighting means within the field of view of which a missile must be positioned in flight, further sighting means for effecting missile gathering, movable protective hood means for protecting said movable sighting means, the hood means including window means through which the line of sight of the movable sighting means can pass, slave means for ensuring that the window is generally aligned with said line of sight during use, the apparatus being characterised in that the further sighting means are carried upon the hood means, and override means are provided to override the slave means such that the hood means, and hence the sighting means, can be moved independently of the movable sighting means.By this arrangement, the further sighting means can be moved in limited independence of the movable sighting means so that a launched missile can be readily gathered and guided into the field of view of the movable sighting means.

One embodiment of missile directing apparatus is described by way of example with reference to the accompanying drawing.

Missile directing apparatus, suitable for mounting on a vehicle, for example a helicopter, has movable sighting means including a mirror 1 carried in a gimbal 2 for nodding movement about an axis A-A, that is to say in elevation, and for rotational movement about an axis B-B, that is to say in azimuth. The mirror is controlled by a known gyroscope arrangement, not shown, so that an observer, shown generally at 3, sees a stable image through a telescope 4 mounted generally below the mirror.

The mirror 1 and its gimbal 2, because they lie outside the vehicle, must be protected from enviromenta I effects; accordingly, a protective hood 5 is provided which is carried by the vehicle for rotation about the axis B-B. The hood 5 carries a window 6 through which the sighting means obtains its field of view. To ensure that the window 6 is always generally aligned with the line of sight, the hood is rotated by a motor and gear mechanism 12. Motor control signals are provided by a control system having a pick-off 10 which detects the relative position of the hood 5 and the gimbal 2, and an amplifier 11 so that the motor is driven in such a direction as to provide a null input to the amplifier. The hood 5 is thus slaved to the gimbal 2 and hence to the azimuthal position of the sight means.The window 6 is chosen to be larger than that required to accomodate the field of view of the sighting means and does not need to be precisely controlled.

Carried upon the hood is a further sight means to provide a gathering tracker 7. The tracker 7 is mounted in gimbal for nodding movement, that is to say in elevation, about an axis C-C. It rotates in azimuth with the hood 5. A pick-off 8 and a torque motor 9 are provided to control the tracker 7 in elevation.

Azimuthal movement of the hood 5, and hence the tracker 7 with respect to the gimbal 2, to aid missile gathering is provided by introducing a demand into the motor control system at 1 3 which is summed with the output signal of the pick-off 10, the resulting control signal effectively overriding the slaving of the hood 5 with the gimbal 2 in azimuth.

In use, the described arrangement functions as follows: when the movable sighting means is used for general surveillance, the override demand signal introduced at 1 3 is set at zero, so that the window 6 is maintained generally centrally positioned with respect to the line of sight of the sighting means. For missile directing, an override demand signal is applied to the motor control system to rotate the hood 5, and hence the tracker 7, in azimuth relative to the line of sight of the sighting mens so that it is positioned to give maximum probability of 'seeing" the missile when launched. The pick-off 8 and torque motor 9 are used to adjust the tracker 7 in elevation.

When the missile is launched and is 'seen' by the tracker 7, steps are taken to bring and to hold the missile on the axis of the tracker 7 and subsequently to bring the axis of the tracker into alignment with the line of sight of the sighting means. The hood 5 is then re-slaved to the gimbal 2.

If the hood 5, and hence its window, is controlled to move in elevation as well a"s about axis B-B in azimuth, the the tracker gimbal with its pick-off 8 and torque motor 9 may be eliminated and similar control system to that described in azimuth could be used.

1. Missile directing apparatus including movable sighting means within the field of view of which a missile must be positioned in flight, further sighting means for effecting missile

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Missile directing apparatus This invention relates generally to missile directing apparatus of the type having movable sighting means within the field of view of which a missile must be in flight in order to be directed onto a target. Because when a missile is launched it does not necessarily enter the field of view of the sighting means a further sighting means, conveniently known as gathering tracker, is often used to track the launched missile so that it can be guided into said field of view. Furthermore, the movable sighting means may have a protective hood in order to avoid detrimental enviromental effects. Such a hood includes a window of limited area and it is therefore arranged to be movable; it is slaved to the movable sighting means so that the line of sight of the latter always passes through the window and is not restricted by the hood. The present invention specifically relates to missile directing apparatus including these features; it has for an objective to provide relatively simple missile gathering in such apparatus. According to one aspect of the invention, missile directing apparatus includes movable sighting means within the field of view of which a missile must be positioned in flight, further sighting means for effecting missile gathering, movable protective hood means for protecting said movable sighting means, the hood means including window means through which the line of sight of the movable sighting means can pass, slave means for ensuring that the window is generally aligned with said line of sight during use, the apparatus being characterised in that the further sighting means are carried upon the hood means, and override means are provided to override the slave means such that the hood means, and hence the sighting means, can be moved independently of the movable sighting means.By this arrangement, the further sighting means can be moved in limited independence of the movable sighting means so that a launched missile can be readily gathered and guided into the field of view of the movable sighting means. One embodiment of missile directing apparatus is described by way of example with reference to the accompanying drawing. Missile directing apparatus, suitable for mounting on a vehicle, for example a helicopter, has movable sighting means including a mirror 1 carried in a gimbal 2 for nodding movement about an axis A-A, that is to say in elevation, and for rotational movement about an axis B-B, that is to say in azimuth. The mirror is controlled by a known gyroscope arrangement, not shown, so that an observer, shown generally at 3, sees a stable image through a telescope 4 mounted generally below the mirror. The mirror 1 and its gimbal 2, because they lie outside the vehicle, must be protected from enviromenta I effects; accordingly, a protective hood 5 is provided which is carried by the vehicle for rotation about the axis B-B. The hood 5 carries a window 6 through which the sighting means obtains its field of view. To ensure that the window 6 is always generally aligned with the line of sight, the hood is rotated by a motor and gear mechanism 12. Motor control signals are provided by a control system having a pick-off 10 which detects the relative position of the hood 5 and the gimbal 2, and an amplifier 11 so that the motor is driven in such a direction as to provide a null input to the amplifier. The hood 5 is thus slaved to the gimbal 2 and hence to the azimuthal position of the sight means.The window 6 is chosen to be larger than that required to accomodate the field of view of the sighting means and does not need to be precisely controlled. Carried upon the hood is a further sight means to provide a gathering tracker 7. The tracker 7 is mounted in gimbal for nodding movement, that is to say in elevation, about an axis C-C. It rotates in azimuth with the hood 5. A pick-off 8 and a torque motor 9 are provided to control the tracker 7 in elevation. Azimuthal movement of the hood 5, and hence the tracker 7 with respect to the gimbal 2, to aid missile gathering is provided by introducing a demand into the motor control system at 1 3 which is summed with the output signal of the pick-off 10, the resulting control signal effectively overriding the slaving of the hood 5 with the gimbal 2 in azimuth. In use, the described arrangement functions as follows: when the movable sighting means is used for general surveillance, the override demand signal introduced at 1 3 is set at zero, so that the window 6 is maintained generally centrally positioned with respect to the line of sight of the sighting means. For missile directing, an override demand signal is applied to the motor control system to rotate the hood 5, and hence the tracker 7, in azimuth relative to the line of sight of the sighting mens so that it is positioned to give maximum probability of 'seeing" the missile when launched. The pick-off 8 and torque motor 9 are used to adjust the tracker 7 in elevation. When the missile is launched and is 'seen' by the tracker 7, steps are taken to bring and to hold the missile on the axis of the tracker 7 and subsequently to bring the axis of the tracker into alignment with the line of sight of the sighting means. The hood 5 is then re-slaved to the gimbal 2. If the hood 5, and hence its window, is controlled to move in elevation as well a"s about axis B-B in azimuth, the the tracker gimbal with its pick-off 8 and torque motor 9 may be eliminated and similar control system to that described in azimuth could be used. CLAIMS

1. Missile directing apparatus including movable sighting means within the field of view of which a missile must be positioned in flight, further sighting means for effecting missile gathering, movable protective hood means for protecting said movable sighting means, the hood means including window means through which the line of sight of the movable sighting means can pass, slave means for ensuring that the window is generally aligned with said line of sight during use, the apparatus being characterised in that the further sighting means are carried upon hood means, and override means are provided to override the slave means such that the hood means, and hence the further sighting means, can be moved independently of the movable sighting means.

2. Missile directing apparatus substantially as described with reference to the accompanying figure.