DE2539626A1 - DEVICE FOR CONTROLLING AIRCRAFT - Google Patents

Description

PATENT ADVOCATE
DR.-ING. HANS LEYH 2539626

D-8 Munich 80,

Lucile-Grahn-Strasse 38

Our symbol: j ^ -j ^ 1 "J " |

Lh / fi

Ferranti Limited Hollinwood, Lancashire England

Device for controlling missiles

The invention relates to a device for controlling missiles, in particular projectiles, e.g. rockets, in particular a device for controlling projectiles by means of a Laser beam.

Laser-guided missiles are known, a laser in a guidance station emitting a beam of infrared radiation emits, along which a missile is guided by a suitable guidance system. An important requirement here is to know the position of the missile, at least in altitude and azimuth, for the appropriate guidance signals can be sent out from the command station to direct the missile into the required position. These signals usually take the form of a modulation of the laser radiation. To avoid getting into the missile one

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Laser must be carried in order to send radiation to the command station, the missile is equipped with a reflector provided that the incident radiation along its path reflected. The control room contains a position-responsive detector to determine the angular position of the missile to be determined relative to a reference direction.

The arrangements for sending information from the control room to the missile vary considerably. Nearly only digital methods are used because of the amount of information to be transported. This requires either the use of a laser with a high pulse repetition rate or a high power CW laser. The receiver circuitry in the missile is very complex to reproduce the analog signals necessary to steer the missile in azimuth and altitude.

The invention is therefore based on the object of a control device for a missile in which the system is simplified both in the control room and in the missile is trained.

According to the invention, this is achieved by receiving devices in the missile that respond to control instructions issued by the Laser beam are transmitted, respond and control devices in the control station that respond to the radiation, which is reflected from the missile to cause the laser to send out the necessary control instructions, the control instructions being in the form of pulses, each of which is a separate control instruction, the nature of which and nature is given by the time that elapses between the impulse and the impulse immediately following it.

The receiving device preferably contains a device

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ORISINAL INSPECTED

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to change the rate of response of the missile to a special sequence of control instructions.

An example embodiment of the invention is illustrated by means of the drawing explained in the

Fig. 1 shows schematically in view the missile and the control station.

Fig. 2 shows the control device in the form of a block diagram.

FIG. 3 shows the mode of operation of the control device according to FIGS

4 shows the receiving device in the form of a block diagram of the missile.

As shown in Fig. 1, the guidance system comprises a control station with a laser on a holder or a frame, so that it can be aimed at any chosen point. The laser can send radiation in the form of a narrow beam onto a target emit and the missile (the projectile concerned) is controlled so that it flies along the beam towards the target. At the rear end of the missile, a reflector is arranged, usually a corner reflector, the laser radiation reflected back to the control station. The missile is also provided with a receiver that responds to the instructions, which are transported to him by the laser beam, responds. In the control station, a detector that can be moved with the laser receives reception the radiation reflected by the missile and a control device in the control station determines the instructions, to be sent to the missile (projectile).

Fig. 2 shows the laser 1 and the control device in the control

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station. The laser emits pulses of radiation in the form of a beam 2 of suitable form. The control device generates the signals to fire the laser and / or to control the Q-switch if a Q-switch laser is used.

Part of the laser radiation that reaches the missile is absorbed by the missile through the reflector that is attached to it, reflected. The reflector is expediently a corner reflector, which essentially absorbs the radiation reflected back along the axis of incidence. Each reflected radiation is picked up by an optical system 3 the detector 4 is focused. This can expediently be a quadrant detector that generates four output signals, the relative values of which indicate the point of incidence of the radiation on the detector. The four outputs are via amplifiers 5 to 8 given to a signal processing unit 9. The outputs of the unit 9 represent the position of the missile in azimuth and height with respect to a reference axis, preferably the axis of symmetry of the quadrant detector.

The azimuth and altitude signals indicate whether the missile is on the required flight path. These signals are given to an encoder 10 where the necessary corrections are determined. The encoder generates one parallel digital output that represents the required control instruction to be given to the missile.

A counter 11 is driven by pulses from a clock pulse generator 12 and produces a parallel digital output similar to that of encoder 10. The parallel outputs the encoder and counter are applied to a comparator 13. The counter 11 and the comparator 13 form a timing control. When the two inputs become identical, an output of the comparator will ignite the laser or activate the Q-circuit and

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also resets the counter 11.

Figure 3 shows the manner in which the control statements are identified. In Fig. 3a the momentum at A is that which was previously sent to the missile, at which point in time the counter 11 of FIG. 2 was reset is. Each tax instruction is given a place after a certain one Length of time following this previous pulse. Four control statements are shown, and are shown accordingly those for steering the missile up and left, up and right, down and left, and down and right. Other signals can be used in addition to or in place of these four signals. Fig. 3b shows the generation a command to control the missile to view it up and to the right of its current trajectory to move. The encoder 10 of Fig. 2 is set to give a digital signal to the comparator 13 so that the counter 11 counts clock pulses for a period of time t before its output is identical to that of the encoder. Thus, after this period of time t, the laser 1 is ignited and the Counter 11 reset.

The advantage of this control method is that the pulse repetition rate of the laser 1 can be low, for example on the order of ten pulses per second. The more complex systems mentioned above require higher pulse repetition rates with high performance CW operation (CW = carrier wave), and thus higher costs for lasers, energy supply and cooling systems.

A projectile controlled in the manner described above will always oscillate, i.e. it does not follow the real required Trajectory when the point of light falling on the detector is small. This is because an instruction for a

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Movement of the projectile, for example, "up and left" is only ended when the missile moves too far away and a "down and right" signal is generated. Fig. 3 shows such a type of control. Alternatively, the light point, falling on the detector, defocused or otherwise modified so that more than one quadrant receives light, before the missile crosses the desired path. The rate of change of the missile or its flight direction can can be progressively reduced using suitable encoders and decoders. This allows the trajectory of the missile can be fine-tuned.

Figure 4 is a block diagram of a receiver of the missile. A receiver 30 receives the control instruction pulses from a detector with which the missile is provided and outputs this to the decoder 31. A counter 32 is provided with clock pulses fed by a clock generator 33 which has the same pulse rate as that of the control station. The outputs of the counter are applied to the decoder 31. The decoder generates azimuth and altitude control signals with the correct polarity depending on the received control instructions and these are signal attenuators 34, 35 for azimuth and Height given to control servo systems accordingly. The attenuators are controlled by signals from the decoder to reduce the Increase or decrease attenuation as required to meet the correct need for the missile's control system to create. A delay unit 36 gives the receiver signal to the counter 32 to reset it.

The receiver works as follows: Immediately after receiving the previous control instruction the counter 32 is reset and starts counting from zero at a rate determined by the clock pulse rate is determined. When the next control instruction is received, the number contained in the counter will be

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scanned by the decoder and this identifies the particular one Tax instruction. The counter 32 is reset again and starts counting from zero at a rate equal to is determined by the clock pulse rate. The required azimuth and altitude signals are generated by the decoder 31.

As already stated, the attenuators 34 and 35 are controlled by the decoder 33. Different control methods are possible. For example, specific control instructions can relate to the strength of the damping to be entered. Alternatively, an automatic control can also be used. With such an arrangement, the decoder can be programmed to to change the attenuation according to a given sequence. For example, suppose the last Control instruction was "up and right" and the next instruction is "down and left", which is a crossover represents the desired trajectory, then the attenuation of the azimuth and altitude signals is automatically increased by one Step through a signal "increase attenuation" from the decoder. A subsequent crossing of the trajectory as a result of the next Control instruction "top and right" leads to even more damping. In this way the rate or speed of the response of the missile progressively reduced so that it flies last along the desired trajectory.

Provision can be made that the attenuation is reduced when the same control instruction is received repeatedly is used to correct any disturbance that has caused the missile to deviate from its trajectory.

The control station can expediently use the emitted and reflected laser pulses to remove the Measure missile from the control station. This can be used to control the detonation of the missile, or another

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Behavior, used by appropriate control statements are given.

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Claims (8)

Claims 1. Device for controlling a missile, in particular of a projectile, with a laser, which is arranged in a control station, to generate pulses of laser radiation toward a target, a reflector device attached to the missile, to reflect a portion of the incident Reflecting radiation back to the control station, characterized by a receiving device in the missile based on control instructions responds, which are given to him by the laser radiation, a control device in the control station, which is responsive to the radiation reflected from the missile to cause the laser to make the necessary To send out control instructions, further in that these control instructions are in the form of pulses, one of which each represents a separate control statement, the nature of which is indicated by the period of time between the Impulse and the immediately preceding impulse has elapsed. 2. Apparatus according to claim 1, characterized net that the control device comprises a detector, which responds to the radiation reflected from the missile to emit electrical signals that determine the course of the missile, with an encoder responsive to these electrical signals, to a parallel provide digital output representing the appropriate control instruction to be sent to the missile, and by timing means for sending the instruction. - 10 - 609812/0760 3. Apparatus according to claim 2, characterized in that the time control device has a Has a counter that is switched by clock pulses and provides a parallel digital output, as well as a comparator to which the outputs of the encoder and the counter are applied and which causes the laser, to emit a pulse of radiation when the two Outputs are identical. 4. Apparatus according to claim 3, characterized in that the ignition of the laser Counter is reset. 5. Device according to one of claims 1 to 4, characterized in that the receiving device has a decoder and a counter, which work together to determine from the time position of a received Radiation pulse the corresponding azimuth and altitude control signals to create. 6. Apparatus according to claim 5, characterized in that the receiving device means Indicates the rate of response of the missile to a particular sequence of control instructions to vary. 7. Apparatus according to claim 6, characterized by attenuators to which the azimuth control signal and the altitude control signal can be applied. 8. Apparatus according to claim 7, characterized e t that the decoder generates signals to control the degree of attenuation of the azimuth and altitude signals that are generated by the appropriate attenuators are introduced. 609812/0760