DE1578299B2 - PROCEDURE FOR RETAINING THE MEETING POINT FOR PASSIVE LOCATIONS IN THE SELF-STEERING PHASE USING PROPORTIONAL NAVIGATION OF JOINTED SHELVES - Google Patents

Description

The invention relates to a method for bringing the meeting point forward for passively locating to angular velocity regulated torpedoes and steered torpedoes in the self-steering phase by means of proportional navigation, in the vicinity of the target there is a switch to the squint angle curve and the squint angle is measured in this way that the enemy will be hit about midships.

Almost all torpedoes are nowadays equipped with an acoustic target seeker (sonar), which allows you to switch to self-steering after the enemy target has been grasped. A rotatable antenna is installed in the head of the projectile as a sensor for target acquisition and for generating the steering commands for the projectile, which automatically directs itself to the target with the help of a so-called "tracking system" and remains aimed at the target, even if the projectile or the target make any movements; it is said that "the antenna is attached to the target", ie the main axis of its directional lobe points in the direction of the target. If the main axis of the directional lobe deviates from the target direction, the antenna measures an angle of incidence of the signal ψ _α , which sets the tracking circuit in motion and directs the antenna back to the target until the reception voltage _{proportional to ψ α} is zero and the tracking circuit is therefore shut down. The follow-up circuit reacts so quickly that it can effortlessly follow the bullet or target movement.

The position of the main axis of the antenna can now be measured against a fixed spatial reference direction (e.g. by gyroscope), and the angle observed is the bearing to the target. One uses in place a gyro a rate gyro, then you can also measure the bearing angle change.

Until the target is reached, the torpedoes are generally guided over a wire that is uncoiled steered by a fire control computer located on board the locking point. The primarily The steering methods used and known here are the collision course method (KKV) and the target coverage method (ZDV). After the target seeker has grasped the target, the self-steering of the Floor switched. The projectile is then steered in the self-steering phase by means of proportional navigation (PN). This PN steering rule is based on the following mathematical equation based on:

Wts = K-p'Wtg differential form (1)

Vis - Kp'Wtg + Ψ _ο integral form (2)

Here, ψ _{ΐ3 represents} the target course for the bullet, y) _tg the bearing from the bullet to the target determined by the seeker head, and K _{n represents} a navigation constant.

angles are measured against the north, pointing to the right. The corresponding angular velocities are denoted by ψ.

A known disadvantage of self-guided, passively locating torpedoes is that the torpedo

always the source of noise to be found in the wake behind the opponent's propeller, starts up. This results in either no hits at all or only very ineffective hits in aft Ship positions.

During World War II the torpedoes were steered according to the dog curve, ie the bearing angle between the torpedo axis and line of sight was kept at zero. The torpedo always hit the enemy aft. Later on, mathematical investigations to improve the steering process revealed that steering according to dog-cornering is a special case of PN navigation. In terms of control technology, steering according to the dog curve means that the gain factor of the training regulator K _p - 1 and the bearing angle between the torpedo axis and line of sight ψ ₀ = O must be set. By superimposing a sinusoidal snaking motion, it was possible in many cases to avoid a hit with the screw and move the point of contact more towards the center of the ship.

Another special case of proportional navigation is the well-known squint angle curve in which, From a mathematical point of view, the deviation of the torpedo axis from the line of sight to the enemy is the squint angle represents.

Proportional navigation based on a dog curve or a squint angle curve is no longer common in the self-steering phase of torpedoes. Rather, proportional navigation with gain factors .K ₇ ,> 1 (5 to 10) is currently preferred, which forces the projectile on a collision course. The disadvantage that the projectile encounters the noise source and thus the screw water continues to exist with the sonar homing heads used. Since when steering on a collision course the enemy target is generally approached at a certain angle and not exactly from the aft direction, the well-known superimposition of a sinusoidal snaking movement makes little sense here - especially because there is a risk that the projectile will straight ahead at the target snakes on the wrong side. To achieve effective hits, it has already been proposed in German patent application P 15 78 298.6 to switch the steering control circuit of the projectile, which is steered according to proportional navigation with a gain factor K _p > 1, to a constant disturbance variable in the vicinity of the target, the amount of the disturbance variable depending on the base deflection of the seeker head and possibly the switch-on distance should be selected. Investigations have shown that this method has a high level of sensitivity to parameters.

There were still mathematical considerations

employed in order to achieve effective hits and a certain insensitivity to parameters in that In the vicinity of the target there is a switch to the squint angle curve, whereby the squint angle is measured in such a way that that the first point of intersection of the spiral path with the opponent's course is about midships.

For a better understanding, solutions for generating the squint angle steering rule will first be described to which the skilled person arrives without inventive step. This is done by hand 1 to 3. It shows

F i g. 1 a general combat situation,

F i g. 2 shows a block diagram of the control loop for realizing the squint angle steering rule in a course-regulated floor,

F i g. 3 is a block diagram of the control loop for realizing the squint angle steering rule in a projectile regulated at angular velocity, which is directly influenced by the homing head.

In FIG. 1 shows a general combat situation with a projectile T in the self-steering phase and an opposing target G. The drawn horizontal angles ψ are measured against the north direction. In detail, the registered reference symbols mean the following:

rpg = opponent's course

v _s = opponent's speed

V ₁ = bullet speed

V «= course of the bullet, at the same time the angle of the
Longitudinal axis of the storey

Ψί = angle by which the pivoting antenna is deflected from the longitudinal axis of the projectile

ψ _α - angle of incidence of the signal on the antenna lobe

y) _tg = bearing angle projectile - enemy

Ä / g = distance between projectile and enemy

According to FIG. 2, the proposed method can be implemented in the case of a projectile that is course-controlled and therefore receives the bearing projectile - target y> _tg as the measured value for the steering, in that one follows the bearing angle ψ, _ε , the measured by the measuring element 22 in the steering controller 23 after switching over by the gain factor K ₁ = 1 is multiplied, the constant signal ψ _{0 is} added. This takes place in the addition element 24, in which an electrical variable corresponding to the squint angle ψ ₀ is superimposed on the value K _p · xp _tg. In principle, this superimposition could also be carried out in the setpoint / actual value comparison element 25. The control deviation Δψ _{ - Vis ~ Ψα acts on the rudder control element in 26. The actual course ψ _η output is returned to the kinematics 21 and the target actual value comparison element 25. An actual value ψ ″ (O) present at the moment of switching from proportional navigation to squint angle curve is superimposed on the actual course output by the rudder actuator 26 in an adder 27 and results in the actual floor course actual course v>.

In the case of a projectile that is not course-controlled but has angular velocity control, the normally pivotable antenna that hangs on the target would have to be set to a fixed angle - namely the negative of the squint angle ψ _{0 - in order to implement the proposed method in a simple manner} —- be discontinued. This is only possible if - as already mentioned - the antenna continues to measure the angle of sound incidence ψ _α , but now directly influences the movement of the projectile regulated for angular velocity in _{such a} way that xp a = 0. In this case, the squint angle steering rule xp _ts = xp _tg + ψ _{0 is implemented} according to the one shown in FIG. 3 block diagram shown:

The angle of sound incidence % p _a is given by the following relationship due to the given geometry

Ψα = Ψίι ~ Ψη— (- Ψη)

- ψ _η is the squint angle specified by a fixed setting of the antenna system with respect to the longitudinal axis of the projectile; in this case it corresponds to the _{angle mentioned earlier + ψ &} (see Fig. 1). It is given by swiveling the antenna of the homing head against the longitudinal axis of the bullet. Within the fictitious course control loop closed by the geometry (below the dashed line in FIG. 3) one receives the fictitious "course setpoint" for the floor

Wts = Ψίζ - (-W ₀ ) - As + Wq

by superimposing the squint angle ψ ₀ in an addition element 32 on the bearing projectile - target \ p _{tg, which is} geometrically present in accordance with the kinematics 31. The squint angle ψ ₀ is not superimposed by feeding in a corresponding electrical variable, but is also already present in the geometry by pivoting the rotatable antenna against the longitudinal axis of the projectile by a corresponding amount.

The fictitious “nominal course value” y> _ts formed geometrically in this way is fictitiously compared in the comparison element 33 with the actual course value ψ _Η. In this way, the geometrically existing angle of sound incidence ψ _{α is obtained} . This angle of sound incidence ψ _α is recognized by a phase discriminator34 in the sonar head and converted into a voltage proportional to ψ _α. This is multiplied by the gain factor .K ₇ in the steering controller 35 and thus forms the target value y> _{ts of} the projectile regulated to angular velocity. By comparing the setpoint value with the actual projectile angular velocity ψ « ¹ in a comparison element 36, the control deviation Δ ψ, = \ p _ts - φ”, which acts on the rudder control element in 37, is obtained. The actual change in angular velocity ψα of the projectile is fed back to the comparison element 36 on the one hand and after formal integration (integrating element 38) and a correction by the actual course value ψ _η (0) of the storey course present at the moment of switching (i = 0) as the actual course ψ «of the kinematics 31 and the comparison element 33 supplied.

The realization of the squint angle steering rule Wis - Wig + Vo ™ Moment of switching from proportional navigation to the squint angle curve in the FIG. 3 will encounter difficulties in practice because usually only a tracking control of the antenna system of the homing head is provided in the floors, but no fixed angle setting in the system.

shot, as is indispensable to the prerequisite for the realization of the squint angle steering rule F i g. 3 was made. In this case, which is by far the most common, it was previously believed that the realization of a squint angle curve is not possible. On the other hand, it is from control engineering Favorable reasons to regulate the projectile to angular velocity.

The object of the invention is therefore to create a control method with which the switchover from a torpedo steered by means of proportional navigation on a squint angle curve can.

To solve this problem, the invention proposes that the gain factor of the steering controller for proportional navigation is set to one at the moment of switching and that an angular velocity disturbance variable ($ ) is fed into the steering controller over a certain time (τ) so that the disturbance variable necessary for the squint curve ψ _εΙ ο _Γ ⁼ ψ ■ τ so becomes.

The advantage of the method according to the invention is in particular that for in the self-steering phase Torpedoes steered by means of proportional navigation are the transition to the squint angle curve in this respect is cheaper than switching on a constant disturbance, because the parameter sensitivity is lower will.

On the basis of FIG. 4 and 5 the invention is to be explained in more detail. It shows

F i g. 4 is a block diagram of the control loop for realizing the squint angle steering rule in a projectile regulated to angular velocity, indirectly via the measured wake of the target seeker head being affected,

F i g. 5 is a control-technically equivalent block diagram to FIG. 4th

F i g. 4 shows the block diagram of a projectile regulated for angular velocity. The change in the geometrical direction finding projectile - target ip _{g determined by the kinematics 41 is determined by the measuring element 42. A disturbance variable change yi _{disturb is} superimposed on the bearing change ψ _ίε determined in this way in the addition element 43. By multiplying the thus formed variable % p _tg +% p _stör with the gain factor K "= 1 in the steering controller 44, the target value ip _{ls of} the projectile course angular velocity is obtained. The nominal value is compared with the actual value of the course angular velocity of the projectile in the comparison element 45, and the control deviation

At first glance, the disturbance variable for a specified period of time is not recognizable as promising. That this route is feasible, however, should be shown on the basis of FIG. 5 will be explained. ^:;

Assuming that in FIG. 4 from the point at which the bearing change ψ _Ιε occurs to the point at which the course ψ _η occurs, there are only linear elements in the steering control loop - and this condition is sufficiently well met in the present case - the integration can be carried out from ψ _Η to ψ «purely formally, as shown in FIG. 5 is shown. In terms of control technology, nothing changes here with regard to the course y> _(i.

It can now be seen from FIG. 5 that the bearing Wts ~ Vtg (0) has arisen fictitiously in front of the summing point with% p _ster. If one interprets the size behind this summation point as a "course setpoint" and sets the gain factor of the steering controller to one, then the steering rule is

> Wts < = Via

+ y> _s tör = Wto +

ie the squint angle rule can be seen. In order to "set" a certain squint angle xp ₀ - c · xp _b (0), must

⁼ VstSr ~ Wig (0) =

sturgeon

V «(°) + Wb (0)

be. So

= yj _ls - ψα

acts on the bullet 46, which is regulated to angular velocity. After integrating the course angular velocity value xp _ti in the integration element 47 and superimposing the actual course value ψ ₍₁ (0)) present at the moment of switching (/ = 0), the actual course value ψ _{Η is obtained} , which is fed to the kinematics 41 .

The measure of feeding in a constant In the above equations, xp _tg (0), y> _b (0) and ■ ψti (0) denote the angles that existed at the moment of switching from proportional navigation to the squint angle curve.

Since ψu (0) already exists in the structure according to F i g. 5 is present - namely as the initial value after the formal integration of FIG. 4, must be final

VsIOr = (1 + C) -V ₆ (O)

be adjusted to a squint angle
W ₀ = C. ψ ₆ (0)

to force. In practice this means that when switching from proportional navigation to squint angle curve, you only have to set the gain factor of the steering controller to one and the constant disturbance with the amplitude fp _{disturb in the steering control loop} for the time

T =

fstör

feed in.

The basis of the acoustics of the homing head is not to be set to a constant angle, Instead, the tracking control loop of the target seeker head is advantageous, as is the case with proportional navigation continue to operate.

For this purpose 3 sheets of drawings

Claims (1)

Claim: Method for moving the meeting point forward for passively locating torpedoes that are regulated at angular speed and steered by means of proportional navigation in the self-steering phase, with a switch to the squint angle curve taking place in the vicinity of the target and the squint angle being measured so that the opponent is hit approximately amidships, characterized in that the gain factor of the steering controller for proportional navigation is set to one at the moment of switching and an angular velocity disturbance variable (ψ) is fed into the steering controller over a certain time (r), so that the disturbance variable required for the squint curve becomes \ p _disturbance = ψ · τ .