DE4007999A1 - Remote controlled projectile or missile - uses camera as sensor for holding missile at required height - Google Patents

Abstract

After the missile etc. has reached the required flight height, it is followed by an optical video sensor, such as a camera, fitted in the missile axis in the flight direction. It is mounted on a platform whose rated rotary velocity is computed according to a formula, related to an amplification factor, measured flexure shift and shift vectors. The rated flight height, imaging interval and flight velocity are also considered. Pref. the platform rated rotary velocity is directly computed from the viewing distance according to a second specified term.

Description

The invention relates to a guided missile and its Steering. This has a target seeker and an imaging one Sensor, e.g. B. a television camera sending their pictures to the ground station (Steering wheel) sends.

Such remote control methods, e.g. B. for unmanned aerial vehicles are known (compare EP 01 48 704 A1).

The imaging method according to the invention and its evaluation is intended to serve to improve the attitude of a missile when using a known inertial stabilized camera platform.

This lightning-assisted height maintenance is solved in a simple manner the claims. It can be a conventional steering computer for relatively small Amounts of data are used.

The invention is explained in more detail in the drawings. It shows

Fig. 1 is a measurement of the image shift,

Fig. 2, the height control by the angle controller,

Fig. 3 is a schematic illustration of the height control by the angle controller,

Fig. 4, the image processing at varibaler viewing distance,

Fig. 5, the image processing to variant A and

Fig. 6, the image processing to variant B.

The invention is based on the following basics:

The corresponding yaw, pitch and roll movements of the central part of the image can be determined from two displacement vectors, which are determined to the right and left of the image center by correlation in two successive images ( FIG. 1).

If the airspeed is known, auxiliary variables for the steering method ( FIG. 2) can be derived from these vectors, such as. B.

• - line of sight to the point of the sensor axis,
• - Height,
• - Course,
• - Roll reference.

The methods described below relate to three different methods for image-based altitude maintenance, ie to replace an altimeter in the missile. In all cases, the vertical angle RP between the FK longitudinal axis and the optical axis of the camera is controlled by controlling the missile so that a constant flight height H is maintained ( FIG. 3).

The only differences are in the calculation of the target rotation speed QPD of the camera platform ( FIGS. 4 to 6).

If, after reaching a certain flight altitude, the camera point is fixed manually or with the help of background tracking at a known distance, then almost any height profile can be generated via a setpoint QPD = f (T). However, the range of this method is limited to the maximum visibility ( Fig. 4).

The following embodiment does not require a fixed breakpoint and is therefore suitable for any range.

Does the missile have the desired flight altitude at the end of the redirection phase  is approximately reached, the target rotational speed of the Camera platform calculated using the following formula:

in which means:

K = gain factor,
ΔN = measured pitch shift, R = from the shift vectors (right and left of the image means and from two successive images the visual distance and
the following are specified:
HS = target flight altitude,
V = flight speed,
ΔT = image interval.

The advantage of this calculation approach is that the altitude depends solely on the tolerances of the airspeed. The remaining errors only influence the line of sight angle and the resulting distance of view ( FIG. 5), and these deviations can be compensated for in the long term via QPD.

In the embodiment according to claim 2, the visual distance is corrected directly to the target value RD via the platform ( FIG. 6). In this case, the desired line of sight is reached more quickly and adhered to exactly, while tolerances of the angle of attack lead to deviations from the target flight altitude.

Claims (2)

1. Remotely steerable missile, characterized in that after reaching a desired flight altitude this is held image-based and for this purpose an optical image sensor (camera), which is arranged in the axis of the missile in the direction of flight, on a platform that calculates with respect to its target rotational speed (QPD) is, according to the formula: where K = gain factor,
ΔN = measured pitch shift, R = from the shift vectors (right and left from the center of the image and from two successive images, the visual distance and
the following are specified:
HS = target flight altitude,
V = flight speed,
ΔT = image interval. 2. Remote-guided missile according to claim 1, characterized characterized in that the plate shape target rotational speed immediately is calculated from the visual distance, according to the formula: QPD = K (RD-R).