DE4124428A1 - Air threat detection and response system - Google Patents

Description

The invention relates to a system for detection and loading response to an air threat.

Such a system can be on the ground, on a ground vehicle, a ship or on board an airplane or missile pers installed and allows the ground station, the ground vehicle, the aircraft or water vehicle in particular re to protect against missiles that threaten them.

This system for air detection and response threat is characterized according to the invention, that it includes:

• - a unit rotatable about an axis;  
• - Means for driving this unit with a rotary movement about this axis;
• - Photosensitive means affixed inside the unit are ordered and capable of the environment of the system to be observed through at least one observation window pay attention to that in the outer peripheral wall of the unit brought;
• - Distance measuring means for measuring the distance between system and threat, and means for one Attack the threat using range-finding Means and the means of attack housed in the unit are;
• - Measuring devices, the angular position of the Specify unit; and
• - processing means which are those of the photosensitive Means, measuring devices and distance Received information received measurement means and give orders to the attack means.

Due to the detection field of the photosensitive means in a plane through the center of the observation window and the axis of rotation of the unit runs For example, detection is carried out via the side angle. We against the rotation of this plane around the axis of rotation of the unit an elevation angle detection can also be carried out. The local The attacker's positioning is Means increased in accuracy so that the attack can neutralize the attacker.

It is for a detection in elevation angle and side angle thus sufficient if the photosensitive agent is little at least capture the field in the rotating plane is contained by the center of the observation window and through the axis of rotation of the unit.  

To detect a threat anywhere in relation to the system according to the invention (if it carried on board a missile), it is advantageous sticks when the unit is continuously ro animals. However, if the threat is necessarily from approaching a single side of the system, it may be enough if the unit has a center on both sides of its axis of rotation position is pivoted. This applies, for example, to a system too that is attached to the ground or on a ship is, or on board a missile that is very large Flying high and capturing enemy missiles and new that should arrive from below.

Preferably, the photosensitive means are several individual detectors, and each individual detector an observation window is assigned.

The distance measuring means preferably consist of a laser rangefinder and / or the attack means consist of a glare laser.

In particular, the mechanism for adjusting the angle of the Laser rangefinder or glare laser a construction Part with a tooth sector, which an endless worm is assigned, which is actuated by a stepper motor becomes; in this case, the optical devices of the Laser rangefinder or the glare laser in this Component of the angle adjustment mechanism may be included.

Preferably, the movable unit is a rotatable hollow wreath formed.

If the system according to the invention on board an aircraft or missile is attached, the axis of rotation of the Wreath preferably with the roll angle axis of the missile pers match.  

In particular, the ring can rotate around a shaft that is fixed is connected to the missile.

Preferably, the outer wall of the wreath is in white considerably flush with the outer wall of the missile fuselage.

Further features and advantages of the invention result from the following description and from the drawing to which Reference is made. The drawing shows:

Fig. 1 is a schematic perspective view of one embodiment of the system;

Fig. 2 is a diametrical section of the movable unit of the system in Fig. 1 through a plane which passes through the axis of rotation of the unit;

Fig. 3 is a sectional view of the movable unit of the system of Figure 1 through a plane perpendicular to the axis of rotation of the unit.

Fig. 4, 5 and 6 sectional views along line IV-IV or VV or VI-VI in Fig. 3;

Fig. 7a to 7d, an embodiment of the laser rangefinder;

FIG. 8a to 8d an embodiment of the cross-fade laser;

Fig. 9 shows the arrangement of the inventive system in an aircraft, in particular missile;

Fig. 10 is a view for explaining the operation of the system;

FIG. 11 is a view for explaining the evaluation of the speed of an attacker; and

Fig. 12 is an overview diagram for explaining how the system works.

The system illustrated in Fig. 1 for detecting and responding to an air threat includes a unit 1 , which in this embodiment has the general shape of a hollow ring and is rotatable about an axis X, X which extends in a first direction, so that the unit can perform a pivoting movement over the elevation angle, as illustrated by an arrow in FIG. 2. For this purpose, the unit 1 in the vicinity of its center Wälzla ger 3 , while shaft bearings 4 for the assembly of the unit 1 are shown symbolically in Fig. 1.

As already mentioned, the unit 1 can be carried on the ground or on a ground vehicle, on board a water vessel or also on board an aircraft, for example an artificial satellite, on board an observation aircraft or combat aircraft or in a missile. On the ground or on board a ship, the pivoting takes place about the axis X, X alternately over an angle of at least about 90 ° on either side of a central position, so that an entire scanning angle of about 180 ° is covered. On board an aircraft, however, a Verschwenkungswin angle of 360 ° is covered, which is done for example by a continuous rotation of the unit 1 about the axis X, X by 360 ° (in this case, about the roll angle axis of the aircraft), or by Back and forth rotation around a central position with an angular deflection of 180 ° each.

In its outer peripheral wall 5 , the unit 1 contains :

• - A first observation window 6 , which covers the front sector A1 of the observation field at a side angle over, for example, 50 °, this window being assigned first photosensitive means 22 (FIGS . 3 and 4);
• - A second observation window 7 , which covers the central sector A2 of the observation field in the side angle over at example 60 °, this window second photosensitive means 23 are assigned ( Fig. 3 and 5);
• - A third observation window 8 , which covers the rear sector A3 of the observation field at a side angle over, for example, 50 °, this window being assigned third photosensitive means 24 (FIGS . 3 and 6);

Furthermore, a window 9 for a laser range finder 25 ( FIG. 3) and a window 10 for a glare laser 26 are provided in the peripheral wall 5 ( FIG. 3).

As can be seen from Fig. 2, the unit 1 is rotatably Lich roller bearings 3 mounted on a shaft 11 which is fixedly connected to its mounting bracket (ground station, water vehicle or aircraft). In the example shown, the unit 1 holds a motor 12 for driving it around the shaft 11, which motor is connected in a rotationally fixed manner to the unit and sets a pinion 13 in rotation, which meshes with a gearwheel 14 which is fixed to the shaft 11 connected. The shaft 15 of the motor 12 , on which the pinion 13 is fastened, is rotatably mounted in a frame 16 connected to the unit 1 . The shaft 15 is fer ner fixedly connected to an indexing disk 17 which cooperates with an angular position encoder 18 which is fixedly connected to the unit 1 .

Furthermore, an electric power supply device 19 and an information processing device 20 are fixedly attached to the mounting bracket.

A rotary coupling or collector device 21 is further provided to enable the electrical power supply of the photosensitive means, the laser rangefinder, the glare laser and the motor 12 starting from the power supply device 19 and to the processing device 20 to forward information resulting from the photosensitive means, the laser rangefinder and the encoder 18 .

Fig. 3 shows in section perpendicular to the axis X, X a unit 1 , inside the first, second and third photosensitive means are attached, which are designated 22, 23 and 24 and the observation windows 6 , 7 and 8 , and the laser range finder 25 , which is assigned to the window 9 , and the glare laser 26 , which is assigned to the window 10 .

As can be seen more clearly from FIGS. 4 to 6, the group consisting of the window 6 and the photosensitive means 22 be oriented towards the front (as agreed) of the mounting bracket in order to occupy part A1 of the observation field. Furthermore, the group consisting of the window 8 and the photosensitive means 24 is oriented towards the rear of the mounting bracket in order to capture a part A3 of the observation field. Finally, the group consisting of the window 7 and the photosensitive means 23 is oriented in such a way that the central part A2 of the observation field is detected. In this way, an observation field of almost 160 ° is scanned by adding the information from the photosensitive means 22 , 23 and 24 to one another.

Furthermore, since the photosensitive means and consequently the observation field (A1 + A2 + A3) rotate about the axis X, X, at the same time as the unit 1 , a large part of the surroundings of the mounting bracket of the unit 1 is scanned by the observation field.

The photosensitive means are, for example, as detec goal lines or matrix of photosensitive elements from  CCD-type trained that sensitive to infrared radiation are.

The pulse laser rangefinder is designed to measure the distance of the Deliver the attacker and possibly an estimate of his ge speed through two successive measurements remote. The laser rangefinder can be used to to determine the distance from which of the glare laser can be used whose range is less than that of the laser rangefinder. It can also be used to interfere with the opposing imager, however at its operating wavelength of, for example, 1.06 µm.

The mechanism for setting the instruction angle for the transmission axis of the laser range finder 25 is shown in FIGS . 7a to 7d. The component or block 27 has a cylindrical outer shape and is firmly connected to a cradle 28 , on the outside of which a toothed sector 29 is attached in a groove 30 of the cradle 28 , in which an endless screw 31 is received, which for a Winkelaus steering Emission axis of the laser beam over the side angle ensures. The two optics groups 32 as well as the transmit / receive subgroups and the timing group are integrated in the interior of the block.

By two pivots 33 , the axis of rotation Y, Y of the rangefinder, which is perpendicular to the axis X, X, is formed, these pivots being pierced in order to enable the supply lines and control lines for the laser beams to pass through.

The block 27 is decoupled from the internal structure of the unit 1 by two bearings (not shown) which are mounted on the two pivots 33 . The angular movement of the optical emission axis of the laser beam is generated by a stepper motor 34 , which drives the tooth sector 29 via the endless screw 31 , and the angle of rotation is controlled by an incremental generator 35 via a control card 36 .

The angular deflection D1 of the adjusting mechanism depends of course on the angular range of the toothed sector 29 and can be, for example, approximately 110 °.

The glare laser in turn has variable waves length or a tunable spectral band so that the of radiation emitted into the detection band of the infrared The attacker's homing device can be placed. The Fo kissing of the energetic laser radiation through the optics of the opposing image sensor leads to this before is dazzled by its photosensitive Elements become saturated or even damaged. The goal Search device is dazzled, and the steering of Angrei disturbed so that it will miss its target.

The mechanism for adjusting the angle of instruction of the axis of the glare laser 26 is illustrated in FIGS. 8a to 8d and analogous to that of the range finder 25 of FIGS. 7a to 7d, apart from the fact that only one emission optics is provided in the latter. It therefore requires less space.

One finds again a cylindrical block 37 , which is firmly connected to a cradle 38 , which has a tooth sector 39 , in whose groove 40 an endless screw 41 engages. The optics 42 are integrated in the block 37 . Fer ner are two pierced pivot 43 on which the bearings are arranged and which allow the passage of the supply and control wires for the laser guns. Likewise, the angular movement of the emission axis of the laser is generated by a stepper motor 44 , and the angle of rotation is controlled by an incremental generator 45 via a control card 46 .

The angular deflection B2 of the instruction angle adjustment mechanism mus can also be about 110 °.  

As shown in FIG. 9, the unit 1 can in particular be attached to an aircraft such as a missile 47 , where the axis X, X then forms the roll angle axis. The unit 1 consists of a rotatable hollow ring which is flush with the outer wall of the missile fuselage and can be rotated about the axis X, X continuously or alternately in both directions. The assembly of the wreath 1 with the flight body 47 can be done in different ways. The missile can be composed of two parts which are assembled by means of the shaft crossing the ring, or it is in one piece, while the ring consists of two half rings which are joined in the diametrical direction.

As shown in FIG. 10, the processing device 20 , which receives the information from the photosensitive means 22 , 23 and 24 and the angle encoder 17 , 18 , can determine the coordinates of any missile that is around the missile 47 , for example in FIG Form of angular coordinates α and β shown in FIG. 10. The photosensitive means namely indicate the position of the missile M in its observation field (A1, A2, A3), while the angle encoder 17 , 18 indicates the position of this field about the axis X, X.

The laser rangefinder allows an estimate of the Velocity of an attacking missile. The speed The attacker's ability V becomes two successive Measurements of distance and direction (α, β) determined, zwi who have a time interval Δt = t₁ - t₀.

FIG. 11 illustrates the flight path of the missile 47 relative to the attacker 48 in the Abfangphase.

At time t₀ the system measures the distance d₁ between Missiles and attackers in the direction that the Side angle α1 and the height angle β1 is given. For now t₁ is the same distance d₂ between missile and An  gripper measured in the direction by the angle α₂ and β₂ is determined.

Let d₀ and d₄ be those of the missile or the threat between two successive measurements Stretching. It is believed that during the time period Δt, 166 ms r 250 ms, the movements of the two missiles are linear, which can be expressed as follows:

d₀ = V₁ Δt and d₄ = V Δt.

The speed V 1 is known, but not V:

The following simplified assumption is made to estimate the distance d₄:
the height angle β changes slightly during the time period Δt, ie

β₁ = β₂.

The following three angles are in the same plane, for that applies:

OO′N + NO′K + KO′J≃ 180 °
Θ₃ + ϕ + Θ₂ ≃ 180 °.

The route covered by the attacker can therefore be eliminated the triangle KO′N can be determined:

d₄² = d₂² + d₃² - 2 d₂ d₃ cos ϕ (2)

The following relationship is also derived from the triangle O'ON:

d₃² = d₀² + d₁² - 2 d₀ d₁ cos Θ₁ (3)

If the two vectors and in that from three rectangles existing triple, and be expressed, so he you hold:

Your dot product is:

Based on this, the following expression can be given:

cos Θ₁ = cos α₁ cos β₁ (4).

You can also write:

cos Θ₂ = cos α₂ cos β₂
from which:

Θ₂ = Arccos (cos α₂ cos β₂ (5).

The following relationship is derived from the triangle OO′N:

Obtained by substituting equation (3) in the above expression one after simplification

The path covered by the attacker can close Lich are given as follows:

The expressions (5), (6) and (8) allow an assessment the distance covered by the attacker and close of parameter V.

It is found that the exact calculation of this speed is difficult because there are measuring errors of eight Pa parameters in the three equations given above, and even several times. This leads to an accumulation of Speed estimation errors.

If there is no precise measurement of the parameter V, then so because of the approximate knowledge of the system when choosing the optimal time for triggering Countermeasures supported for triggering evasion maneuvers or to activate the glare laser.

Fig. 12 is an overview diagram for explaining the operation of the system.

The electrical power supply device 100 feeds, inter alia, the drive mechanism 101 for the movable unit (ring) 102 , in particular its optics groups 103 and detectors 104 , and the incremental encoder 105 , which outputs information to the processing device 106 (angle position for angle of elevation and side angle, α, β). After confirmation of the threat 107 , taking into account management 108 of the various threats, the angular setting 109 of the range finder 110 is made via the incremental generator 111 (α) and the incremental generator 112 (β). A controller 113 of angular deflection is inserted between the processing device 106 and the unit 102 , as is a controller 114 of the laser activation between the unit and the range finder. The rangefinder 110 enables an estimate of the speed of the attacker 115 and a localization of the threat 116 , and by means of these parameters the angle setting of the glare laser 117 can be set via the incremental generator 118 (α) and the incremental generator 119 (β) they follow, as does the triggering of laser activation 120 , before proceeding to detection of the subsequent threat 121 . The parameters 115 and 116 are also transferred to an interface 122 which, after analysis (at 123 ), makes a choice between bait 124 , camouflage 125 or glare ( 117 ).

The system according to the invention ensures the functions of Monitoring, recording and, if necessary, tracking the Localization and glare to the attacker.

Any threat that is within the surveillance zone can do a distance measurement process as well as subsequent trigger the glare of the opposing infrared targeting.

The range of the rangefinder is clearly below half of infrared signal acquisition. So you start with an estimate of the direction of the threat before trying the distance between missiles (for example) and attackers then measure the speed to extrapolate the threat.

In the monitoring and recording phase, the system issues the Angular position of the attacker. In the localization phase se is the direction of the threat of information about Distance and speed completed. The knowledge the attacker's near past also allows a refined localization.  

At a distance greater than the blind distance targeting device, the system can Trigger glare on the attacker's image sensor.

Below are two working examples of this system explained in the event that this on an aircraft such is attached to a missile. In the first example it is believed that the movable unit or the wreath rotates continuously while in the second example is taken that this unit alternately in opposite set directions rotates.

1. Continuous rotation of the unit Monitoring mode

It is assumed that the monitoring device (photosensitive means) in the course of their rotation and after saving the background various signals perceives. In this first stage, who can be accepted that these points are not yet a potential threat represent. It can be false alarms or one or more attackers in a noisy one Act environment.

After identifying the signals with a significant level are taken into account those who have a particular Exceed threshold. After a second scan the direction (α₂, β₂) for the second pass perceived points are saved. Then it becomes a detec mode switched.

Detection mode

A digital elimination can be a first elimination certain natural sources of interference. Man then differentiates between the attackers and unfiled baits in two ways:

• a) through software processing, with different algo rithmen come into consideration and a first approach in it may exist after the third scan Consider signals, their intensity, shape and Direction (α₃, β₃) in the sense of an approximation to that Evolve system-carrying aircraft;
• b) by spectral discrimination of the detector Rows of captured radiation can cause enemy flight body separated from baits in the area become.

After confirmation of the presence of one or more Be threats go to the localization phase. In the The second stage is the number of confirmed bedro reduced significantly.

Localization mode

Two configurations can be considered:

• 1) The captured attackers are in the by the Range finder not covered area. The distance Then, it cannot be estimated, much less the speed of the threat. The system must then based on the angular localization (α₃, β₃) only the time at which countermeasures are triggered or determine evasive action.
• 2) The attackers are in the by the Range finder covered zone. The designated Threats are then processed sequentially, in the order of their appearance in the direction of rotation of the Unity (of the wreath).

After the threats have been confirmed, the incremental Range finder generator the side angle of the first threat brought to an immediate setting  the optical axis of the laser to be emitted trigger on the angle α₃; subsequently is the control of the laser activations with the Time of passage of the emission axis by the rotation angle β₃ synchronized. There can then be two situations occur:

• a) The rangefinder does not measure any distance, either because the attacker is out of his possible range or because the laser pulses have missed their target.
  In this case, move on to the subsequent threat and continue working as before.
  At the end of the fourth scan and after the direction (α₄, β₄) is updated again, the distance measurement for the first threat is carried out again. If the distance measurement is still not possible, the situation described in the previous paragraph is returned.
• b) The rangefinder manages to output the distance information d 1. If the attacker is in dangerous proximity to the aircraft (missile), camouflage or countermeasures must be triggered immediately.
  If, on the other hand, the attacker is at a sufficient distance, the next scan is waited for to take a second measurement of the distance d₂, from which the approximate speed of the threat is derived using the formulas given above.

After analyzing the parameters d₂, V, α₅ and β₅ an Ent divorce over a glare measure.  

In this case, the setting of laser emissions axis made in the angle α₅, and during the passage this axis through the angle of rotation β₅ are laser pulses triggered to blind the attacker's homing device.

Then you go to the processing of the second Bedro hung over etc.

2. Unit with alternating rotation

The monitoring and recording procedures are analog those previously described.

Localization mode

The confirmed threats are in line here processed according to their urgency. The alternating Rotary movement of the wreath is due to a deflection of the Detected means reduced and is some Milliradian on both sides of the angle β₃ at which the An gripper was registered with the first priority.

After refining its localization and determining the new direction (α₄, β₄) becomes the side angle of the Bedro hung to the incremental generator of the rangefinder guided. The optical emission axis is then from that Angle α₄ off, and the wreath is then rotated angle β₄ moves so that the optical laser emission axis together with the assumed direction of the attacker falls, prompting a series of laser pulses immediately is triggered. Two situations can occur:

• a) The rangefinder does not measure any distance, ent neither because the threat is outside its realm far away, or because the laser pulses hit their target have missed. Depending on the relative urgency Priorities 1 and 2 can be decided Determine the direction of priority 1 threat  refine and then measure the distance again, or directly on the localization the threat of priority 2 and the An to process the gripper with the first priority later.
• b) The rangefinder succeeds in measuring the distance of the attacker d 1 and then d 2, so that the speed of the latter can be determined approximately.
  Depending on the amplitude of the parameters d₂ and V, it can be considered useful to take additional measurements to refine the localization, or to camouflage or disrupt the attacker. In the latter case, the axis of the glare laser is set in the direction (α₄, β₄) of the attacker, and laser pulses are released to blind the opposing homing device.
  Then go to priority 2 (or 1) threat processing, etc.

Claims (13)

1. An air threat detection and response system, characterized in that it comprises:

• - A unit ( 1 ) which is rotatable about an axis (X, X);
• - Means ( 12 ) for driving the unit ( 1 ) with a rotary movement about this axis (X, X);
• - Photosensitive means ( 22 , 23 , 34 ) which are arranged inside the unit ( 1 ) and are suitable for observing the surroundings of the system through at least one observation window ( 6 , 7 , 8 ) which is located in the outer peripheral wall ( 5 ) the unit ( 1 ) is attached;
• - Distance measuring means ( 25 ) for measuring the distance between the system and the threat and means ( 26 ) for attacking the threat, these distance measuring means ( 25 ) and the attack means ( 26 ) in the unit ( 1 ) attached are;
• - Measuring means ( 17 , 18 ) which indicate the angular position of the unit ( 1 ) at any time; and
• - Processing means ( 20 ) which receive the information given by the photosensitive means ( 22 , 23 , 24 ), the measuring means ( 17 , 18 ) and the distance measuring means ( 25 ) and commands to the attacking means ( 26 ) output.

2. System according to claim 1, characterized in that the unit ( 1 ) rotates continuously about its axis of rotation (X, X). 3. System according to claim 1, characterized in that the unit ( 1 ) performs an oscillating movement about its axis of rotation (X, X) on both sides of a central position. 4. System according to any one of claims 1 to 3, characterized in that the photosensitive means ( 22 , 23 , 24 ) observe at least the field which is contained in the rotating plane through the center of the observation window ( 6 , 7th , 8 ) and the axis of rotation (X, X) of the unit ( 1 ). 5. System according to one of claims 1 to 4, characterized in that the photosensitive means ( 22 , 23 , 24 ) consist of several individual detectors and that an observation window ( 6 , 7 , 8 ) is assigned to each of the individual detectors. 6. System according to any one of claims 1 to 5, characterized in that the distance measuring means are formed by a laser range finder ( 25 ). 7. System according to any one of claims 1 to 6, characterized in that the attack means are formed by a glare laser ( 26 ). 8. System according to claim 6 or 7, characterized in that the adjusting mechanism for the angle of the laser removal meter ( 25 ) or the glare laser ( 26 ) has a component ( 27 , 37 ) with an angle sector ( 28 , 38 ) , to which an endless screw ( 31 , 41 ) is assigned, which can be activated by a stepper motor ( 3 4, 44). 9. System according to claim 8, characterized in that the optical means ( 32 , 42 ) of the laser range finder ( 25 ) or the glare laser ( 26 ) in the component ( 27 , 37 ) of the mechanism for adjusting the angle are arranged. 10. System according to one of claims 1 to 9, characterized in that the unit is designed as a rotatable hollow ring ( 1 ). 11. System according to claim 10, which is mounted on board a flight device such as a missile, characterized in that the axis of rotation of the ring ( 1 ) coincides with the roll angle axis (X, X) of the aircraft ( 47 ). 12. System according to claim 11, characterized in that the ring ( 1 ) rotates about a shaft ( 11 ) which is fixedly connected to the aircraft ( 47 ). 13. System according to claim 11 or claim 12, characterized in that the outer peripheral wall ( 5 ) of the ring ( 1 ) is at least approximately flush with the outer wall of the missile fuselage ( 47 ).