EP0401693A1 - Method for improving the accuracy of hit of a controlled missile - Google Patents

Abstract

A description is given of a method for improving the accuracy of a programmed flying missile influenced by trajectory disturbances, the desired trajectory of the missile accelerated in the end phase of the trajectory being provided before and during the acceleration with a trajectory lead for the purpose of compensating the trajectory disturbances. <IMAGE>

Description

The invention relates to a method for improving the accuracy of a programmed flying missile influenced by path disturbances.

Usually, missiles that are supposed to fly to a specific target are equipped with a seeker head that is able to identify the target to be fought on the one hand even in the presence of malfunctions, and on the other hand to pursue the target after the target is recognized and thus for an autopilot Generate guidance signal. Such a missile or a method for targeting a projectile or missile which is self-controlling in its final flight phase along an elongated trajectory and from which a steeper target actuation takes place after a target has been recorded, the stretched trajectory initially being retained after the target object to be controlled has been detected, DE 33 03 763 C2 is known before a pitch angle control for the transition from the straight trajectory into a steeper target approach trajectory takes place with a further shortening of the distance to the target object. There, on board the missile or projectile, the theoretical flight behavior of its specified flight behavior upon transition into a specified, stretched-inclined trajectory becomes its theoretical The time of impact determines from which for the steeper target approach path in the target object a delay period for the temporary retention of the stretched trajectory is derived on board the projectile or missile from the point of view of the target up to the time of leaving the trajectory trajectory by changing the pitch angle into the target approach path. The projectile or missile is equipped with a target seeker.

US-A 45 22 356 discloses submunitions that can be released from a container and are each equipped with a seeker head.

A method for target control of remote control bodies, in particular torpedoes, and devices for practicing this method are known from DE 18 15 727 C1. There, depending on target data determined by acoustic location, of a predetermined known steering method, e.g. Pursuit course, proportional or target coverage navigation, when reaching a predetermined target value for the approach of the steering body to the target, switched to a pursuit course after a squint dog curve, the squint angle by an angle larger than the lead angle for standing bearing according to the proportional navigation and in particular greater than one If necessary, the squint angle used for the approximation is already used. As a measure of the degree of approximation, the remaining running time is used, which the torpedo would need to continue running on the previous approximation krus until the target point is reached, and the squint angle changeover is carried out when a predetermined target value of the remaining running time is reached.

Projectiles of this type equipped with a seeker head have a high level of electromechanical complexity, which is why DE 35 22 154 A1 has set itself the task of providing a maneuverable seeker submunition for combating armored vehicles To design target objects in a target area in such a way that, despite the more technologically modest equipment, submunitions still perform well compared to conventional end-phase-steerable submunitions, ie they have an effect on the target that is better than that of a submunition that is slowed down on a parachute. This task is solved there in that the submunition is designed as a dive projectile with a structurally stable sensor and with an aerodynamic positioning system for causing a circular wobble movement during the steep descent into the target area and for sensor-guided end-phase course correction for direct gliding to the dedicated target object.

The invention has for its object to provide a method of the type mentioned, with which a target control of a fixed or a movable target with high accuracy is possible without the missile is equipped with a seeker head, a high accuracy is also achieved , if path disturbances such as eg strong ground winds.

This object is achieved in that the target trajectory of the missile accelerated in the trajectory end phase is provided with a path reserve before and during acceleration to compensate for the path disturbances. The flight path ahead is preferably precalculated in a orbit extrapolation model in accordance with the ideal target position and the current actual position of the missile and in accordance with further flight condition variables, with the resultant predicted hit error in a orbit extrapolation unit via a control unit to reduce the hit error of path corrections of the target path be determined. In order to achieve a very small hit error when carrying out the method, the web extrapolation is preferably carried out in several iterations. Here, ie at The trajectory extrapolation carried out in several iterations preferably takes into account the future acceleration profile of the missile, so that, including future trajectory disturbances and taking current external trajectory disturbances into account, a desired trajectory results with a minimal hit error. The target path optimized in this way serves as a reference or target specification for an autopilot of the missile.

• Fig.1 eine Blockschaltung zur Verdeutlichung des Verfahrens zur Verbesserung der Treffgenauigkeit eines programm­iert fliegenden Flugkörpers, und
• Fig.2 eine grafische Darstellung des Einflusses einer Bahn­störung auf die Flugbahn des programmiert fliegenden Flugkörpers bzw. auf seine Treffgenauigkeit.

Further details, features and advantages of the method according to the invention are described below with reference to the drawing. It shows:

• 1 shows a block circuit to illustrate the method for improving the accuracy of a programmed flying missile, and
• 2 shows a graphic representation of the influence of a path disturbance on the trajectory of the programmed flying missile or on its accuracy.

If a missile does not have a seeker head because this should be saved for cost reasons, for example, or because the seeker head would not be suitable for recognizing the target to be combated, or because the geodetic position of the target to be combated is known from prior clarification, which in particular for stationary targets such as bridges, buildings or the like. the case is, the missile can only move along a programmed trajectory to the target to be fought. It is assumed that the programmed flying missile both its ideal target path, which leads it to the target to be fought, from pre-programmed data or by transmission via a so-called. Data-link knows, as well as sensors and / or an inertial navigation unit, which provides the missile with its actual position. This situation is shown schematically in a block diagram in FIG. A web extrapolation model 10 is closed with a control unit 12 a self-contained system connected, which is indicated by the two arrows 14 and 16. The web extrapolation model 10 has two inputs 18 and 20 and one output 22. The input 18 is connected to the output 24 of a reference unit 26, which is indicated by the arrow 28. The reference unit 26 has an input 30 through which data preprogrammed into the reference unit 26 are input.

The output 22 of the orbit extrapolation model 10 is connected to an input 32 of an autopilot 34, which is illustrated by the connecting line 36. The autopilot 34 has a second input 38 and an output 40, the output 40 of the autopilot 34 being connected to an actuating system 42. The control system 42 is connected to the missile dynamics illustrated by block 44. The output 46 of the missile dynamics 44 represents the trajectory of the missile. This trajectory is characterized by the trajectory disturbances indicated by the arrow 48, which are, for example, gusts of wind, ground wind or the like. acts, influences. Sensors 50 are used to detect the flight path or the flight path disturbances, the output 52 of the sensors 50 being connected to the second input 38 of the autopilot 34. In addition, the output 52 of the sensors 50 is connected to an inertial navigation unit 54, at the output 56 of which the respective actual position of the missile is given. The actual position of the missile is entered through the input 20 of the orbital extrapolation model 10 and the ideal target path of the missile is entered through the input 18 of the orbital extrapolation model 10. The exit 22 of the orbit extrapolation model 10 represents the target path of the missile, while the arrow 14 between the orbit extrapolation model 10 and the control unit 12 represents the hit error.

Depending on the accuracy of the sensors 50, the autopilot 34 and the positioning system can be used 42 to influence the missile dynamics so that the real trajectory of the missile despite the external disturbances - which are indicated by the arrow 48 - leads to the target to be combated.

• 1. Bei der Bewegung des Flugkörpers in einem Windfeld ergibt sich ein resultierender inertialer Geschwindigkeitsvektor v als Überlagerung, d.h. als Vektorsumme des Geschwindig­keitsvektors v_a gegenüber ruhender Luft und des Windge­schwindigkeitsvektors v_w . In Fig.2 ist eine Vektordar­stellung in einer Horizontalebene x-y gezeichnet, ent­sprechendes gilt selbstverständlich auch für die zu dieser Horizontalebene senkrechte Vertikalebene. Ergibt sich nun in einem stationären Zielanflug der inertiale Bahnwinkel b₁ als resultierende Flugrichtung zum Ziel mit der Geschwindigkeit v_a1 und der Windgeschwindigkeit v_w zur resultierenden Geschwindigkeit v₁, so ändert sich bei Schuberhöhung die Geschwindigkeit v_a1 zur Ge­schwindigkeit v_a2, wobei der Windgeschwindigkeitsvektor v_w gleich bleibt. Das bedeutet jedoch, daß die aus v_a2 und v_w resultierende Geschwindigkeit v₂ als neue inertiale Geschwindigkeit auftritt, die mit der x-Achse einen von b₁ abweichenden Winkel b₂ einschließt. Es ergibt sich also ein Winkelfehler Δb als Differenz zwischen den beiden genannten Winkeln b₁ und b₂ in der Zielpunkt­richtung und folglich eine Verringerung der Treffgenau­igkeit, da Bahnkorrekturen des beschleunigten Flugkörpers im Ergebnis zu großen Ablagen führen.
• 2. Ein zur Geschwindigkeitserhöhung dienendes Triebwerk des Flugkörpers wird typischerweise seine Schubkraft in Flugkörper-Längsrichtung, d.h. in Richtung des Vektors v_a entwickeln. Befindet sich der Flugkörper vor der Beschleunigungsphase im Schiebeflug, so bewegt er sich inertial in der in Fig.2 dargestellten Horizotalebene x-y nicht in der Flugkörper-Längsrichtung sondern in einer von der Windgeschwindigkeit v_w abhängigen resul­tierenden Bahnrichtung, die durch den Autopiloten 34 (s. Fig.1) in Zielpunktrichtung gedreht wird. Wird nun der Flugkörper beschleunigt, so wird er nicht in der inertialen Bahnrichtung zum Ziel sondern in seiner Flugkörper-Längsrichtung beschleunigt und kann nur unter unrealistischen Manövereingriffen des Autopiloten 34 zum zu bekämpfenden Ziel korrigiert werden, was ebenfalls zu einer Verringerung der Treffgenauigkeit führt. Ent­sprechendes gilt selbstverständlich auch für die Bewegung in der Vertikalebene.

If the missile is to be strongly accelerated to increase the impact velocity at the target to be combated in the final phase of the trajectory in order to improve the effectiveness of the missile, the following problems are illustrated in FIG. 2 with a missile without a seeker head:

• 1. When the missile moves in a wind field, a resulting inertial speed vector v results as a superimposition, ie as a vector sum of the speed vector v _a with respect to still air and the wind speed vector v _w . A vector representation is drawn in a horizontal plane xy in FIG. 2; the same applies of course also to the vertical plane perpendicular to this horizontal plane. Now results in a stationary target approach the inertial orbit angle b₁ as the resulting flight direction to the target with the speed v _a1 and the wind speed v _w to the resulting speed v₁, so the speed v _{a1 changes} to the speed v _a2 when the thrust is increased, the wind speed vector v _w stays the same. However, this means that the velocity v₂ resulting from v _a2 and v _w occurs as a new inertial velocity, which includes an angle b₂ deviating from b₁ with the x-axis. So there is an angle error Δb as the difference between the two angles b₁ and b₂ mentioned in the direction of the target point and consequently a reduction in the accuracy, since path corrections of the accelerated missile result in large deposits.
• 2. A missile engine used to increase the speed typically becomes its thrust develop in the longitudinal direction of the missile, ie in the direction of the vector v _a . If the missile is in the push flight prior to the acceleration phase, it moves inertially in the horizontal plane xy shown in FIG. 2 not in the longitudinal direction of the missile but in a resulting orbital direction dependent on the wind speed v _w , which is determined by the autopilot 34 (see FIG. Fig.1) is rotated in the direction of the target point. If the missile is now accelerated, it is accelerated not in the inertial orbital direction to the target but in its longitudinal direction and can only be corrected under unrealistic maneuvering by the autopilot 34 to the target to be combated, which likewise leads to a reduction in accuracy. The same naturally also applies to the movement in the vertical plane.

The two problems mentioned, which lead to a deterioration in the accuracy of the hit, can be solved if the target path of the missile, which is indicated by the connecting line 36 between the orbit extrapolation model 10 and the autopilot 34 in FIG. 1, occurs before and during the acceleration of the missile a path reserve is provided which compensates for the error sketched for the horizontal plane in FIG. 2 by trajectory disturbances (see arrow 48 in FIG. 1). For this purpose, in the orbit extrapolation model 10, the flight path ahead is calculated in advance in accordance with the ideal target position (input 18 of the orbit extrapolation model 10 in FIG. 1) and in accordance with the current actual position (input 20 of the orbit extrapolation model 10 in FIG. 1), and in accordance with further flight state variables. From the resultant predicted accuracy error, 12 orbit corrections of the target path are determined in the web extrapolation unit via the control unit, which lead to a reduction in the accuracy error. With this orbit extrapolation, which preferably runs in several iterations, the future acceleration profile of the Missile taken into account so that a target trajectory arises, which, including future trajectory disturbances and current external trajectory disturbances, minimizes the hit error. This optimized target path (connecting line 36 in FIG. 1) serves the autopilot 34 as a reference or target specification.

Claims (5)

1. A method for improving the accuracy of a programmed flying missile influenced by orbital disturbances,
characterized by
that the target trajectory of the missile accelerated in the trajectory end phase is provided with a path reserve before and during the acceleration to compensate for the path disturbances. 2. The method according to claim 1,
characterized by
that the flight path ahead is calculated in advance in a web extrapolation model in accordance with the ideal target position and the current actual position and in accordance with further flight condition variables, the path predictions of the target path being determined in a web extrapolation unit using a control unit to reduce the target error. 3. The method according to claim 1 or 2,
characterized by
that the web extrapolation is carried out in several iterations. 4. The method according to claim 3,
characterized by
that the future acceleration profile of the missile is taken into account in the orbital extrapolation carried out in several iterations, so that including future path disturbances and taking into account of current external trajectory disturbances results in a target trajectory with minimal accuracy. 5. The method according to any one of the preceding claims,
characterized by
that the optimized target path is used by an autopilot of the missile as a reference or target specification.

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