DE3741498A1 - ARRANGEMENT FOR DETERMINING THE ROLLING ANGLE POSITION - Google Patents

Description

The invention relates to an arrangement for determining the Roll angle position of a missile flying out of a tube, as they are closer in the preamble of claim 1 is defined.

It is with missiles rotating about their longitudinal axis often required, the roll angle position of the missile to be measured relative to the geodetic reference system. So is used for example with guided projectiles for the Trajectory correction both the deviation of the real one from the theoretical path as well as the roll angle position determined, then the correction pulse in such a Roll angle to trigger that he observed Deviates counteracts (see e.g. DE-OS 25 43 606).

The roll angle position of the missile can be both optical as well as be determined magnetically. An optical roll angle position measurement has the disadvantage that it is sensitive to brightness and therefore z. B. at Night or adverse environmental conditions (snow, bluer Sky) allows only incorrect measurements.  

When determining the roll angle position on magnetic A magnetic field sensor is located in or on the missile, which is the roll angle position in relation to the earth's magnetic field determined, the sensitivity axis runs perpendicular to the direction of flight. So it will be Taking advantage of the fact that the vector of the magnetic field of the Earth only horizontally above the equator Earth's surface lies while it is in the other areas is inclined to the ground and thus a vertical component owns, which is used for roll angle position measurement can be.

When flying towards the magnetic north pole via the magnetic field sensor due to the missile rotation receive a sinusoidal signal around the flight axis, the Maxima and Minima the magnetic vertical field of the earth are proportional so that an "up-down" determination is possible. However, the flight direction deviates from the magnetic north direction, so it shows from the sensor maximum magnetic field no longer measured vertically below but in a direction that is increasingly increasing through the Inclination angle is determined. When flying east for example, there is an error in the FRG of 25 °.

It is therefore the object of the present invention, a To further develop the arrangement of the type mentioned at the beginning, that when the missile moves in any Direction a clear angle assignment to the phase of the Sensor signal is obtained.

The object is achieved by the features of characterizing part of claim 1 solved.  

Particularly advantageous configurations result from the subclaims.

Further advantages of the invention are shown with the help of Exemplary embodiments with reference to figures in the following explained in more detail.

Show it:

Fig. 1 is a schematic representation of an arrangement according to the invention and

FIG. 2a to FIG. 2c, the curve of the output signals of the magnetic sensors as a function of the distance of the projectile from the muzzle.

In Fig. 1, 10 and a missile 20 with the mouth-side part of a pipe (. E.g. a gun) from which the missile is fired 10, is shown. The magnetic field sensors 11 and 12 are located inside the missile 10 . These magnetic field sensors can, for example, be sensors that use the magnetoresistive effect. The first sensor 11 has only one sensitivity axis perpendicular to the direction of flight, while the second magnetic field sensor 12 has two sensitivity matters lying in a plane perpendicular to the direction of flight. The corresponding sensors are commercially available and therefore do not need to be explained in more detail.

Furthermore, in FIG. 1, H denotes the field strength of the earth's magnetic field, which can be broken down into a vertical component H _V and a horizontal component H _H. The inclination angle is marked with α , which lies between 60 and 70 ° in the FRG.

The mode of operation of the invention is briefly described below Arrangement described.

When the projectile 10 emerges from the tube 20 , the rear magnetic field sensor 12 is moved past the reference magnet 21 , while the front sensor 11 already detects the earth field. This enables the phase position of the projectile to be determined with respect to the external magnetic field. Due to the biaxial arrangement of the sensor axes of the sensor 12 , the spatial position of the reference magnet 21 within the plane spanned by the two sensor axes can be determined by the following relationship:

where Ax and Ay are the amplitudes of the partial sensors which characterize the sensor axes, γ the angle between the partial sensor of sensor 12 oriented in the x direction and the direction of the reference magnet and tx the time of the measurement.

The reference signal received by the second magnetic field sensor 12 on the basis of the magnet 21 thus determines a specific angular position of the missile, which can be clearly assigned to the signal of the front sensor 11 .

These relationships are shown again in FIGS. 2a to 2d. In this case, 2a, Fig., The measured with the first sensor 11 vertical magnetic field eluting with to the time is indicated, in which the sensor 11 exits the mouth of the tube 20 and the corresponding to the respective magnetic field sensor amplitude A 11 plotted on the vertical axis is. The voltage amplitudes A _x and A _{y of} the partial sensors of the sensor 12 are shown in FIGS . 2b and 2c. When the reference magnet 21 flies past, there are pronounced maximum values.

In Fig. 2d is that with the help of Eq. (1) determined value γ reproduced, which is 19 ° in the example shown.

The roll orientation of the floor to any one Time on the trajectory is due to the following Consideration determined.

The front sensor 11 has an amplitude curve A (t) according to the following relationship:

A (t) AO sin ( l _o t + ϕ )

The initial phase of this signal can be equated with the angle from the measurement of the two rear partial sensors of sensor 12 ( ϕ = γ ) . At the same time the signal (or the amplitude signal A _x) serves as a trigger for the front sensor 11, which at this time to receive its measurement and ω determines the speed.

The roll position α can be determined from the determined speed ω at any point in time with a known initial phase:

α (t) = ω t + γ (to)

determine.

The changes on a ballistic trajectory Angle of attack of the missile, but not the direction of flight. It therefore only changes the amplitude of the Sensor signal and not the phase position, so the shape the trajectory has no influence on the roll position determination. According to the invention, for the roll position detection Phase position evaluated.

Claims (2)

1. Arrangement for determining the roll angle position of a missile ( 10 ) flying out of a tube ( 20 ) with the aid of a first magnetic field sensor arranged in or on the missile ( 10 ), characterized by the features:

• - The missile ( 10 ) has a second magnetic field sensor ( 12 ) arranged at a predetermined distance in the direction of flight;
• - On the tube ( 20 ), a reference magnet ( 21 ) is provided, so that the second magnetic field sensor ( 12 ) when flying past the reference magnet ( 21 ) generates a reference signal determining the instantaneous angular position of the missile ( 10 ).

2. Arrangement according to claim 1, characterized in that the second magnetic field sensor ( 12 ) has two sensitivity axes lying in a plane perpendicular to the direction of flight.