JPH0663716B2 - Homing guidance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a missile for a ground target (ground missile).
Homing guidance device.

(Prior Art) There are ground-to-ground missiles, air-to-ground missiles, and the like, and many of them have a flight path that is conductive. The homing guidance axis of a homing guidance device in a missile in which a flight path guides points to the sky for the first period after the missile is launched, then crosses the horizon, and then to the ground. This homing guidance system is designed to fly a missile without guidance while the antenna pointing axis is facing the sky, and then search for the target by the active homing method after the antenna pointing axis is facing the ground to detect the target. It is normal. In this type of homing guidance system, not only the emission of radio waves for active homing is not necessary during the period when the antenna pointing axis is pointing to the sky, but it is not emitted to prevent missiles from being detected. Is preferred. Therefore, a method has been conventionally used in which the emission of radio waves is stopped before the time when the directional axis of the antenna crosses the horizon and the radio waves are emitted from that time for active homing.

In the conventional homing guide device, when the emission of the radio wave is started, it is determined by a timer or a posture sensor. The timer starts timing from the time the missile is launched, and commands the emission of radio waves (that is, the start of active homing) when the predicted required time from the launch until the directional axis of the antenna crosses the horizon. The attitude sensor detects the attitude of the missile, determines from the attitude when the directional axis of the antenna crosses the horizon, and commands the emission of radio waves at that time.

(Problems to be solved by the invention) However, the time from the launch of the missile until the directional axis of the antenna crosses the horizon is affected by the attitude and speed of the missile, so it is not always constant, and the missile is not constant. It differs considerably in each case. Therefore, at the start of the radio wave emission commanded by the timer, the antenna often shifts considerably before or after the antenna crosses the horizon. Therefore, the conventional homing guidance device using a timer has a drawback that a missile is detected by a radio wave or the start of active homing is delayed and the search of a ground target is likely to fail. Attitude sensors, on the other hand, can detect when the antenna's directional axis crosses the horizon fairly accurately, but are very expensive.

Therefore, an object of the present invention is to provide an inexpensive homing guidance device, in which the guided missile is difficult to detect the radio wave, the search for the ground target by the active homing is started at an appropriate time, and the cost is low.

(Means for Solving Problems) The present invention provides a homing guidance device that does not emit radio waves for active homing during the initial period of flight of a missile and starts the emission from the middle of the flight. The detection means for detecting the intensity of the radio wave received by the antenna placed in the, and the detection of the change of this intensity from a minute value corresponding to the radio wave in the sky to a large value corresponding to the radio wave from the ground. The missile is provided with a direction detecting means for detecting that the direction of the directional axis of the missile has crossed the horizon, and a radiation starting means for starting radiation by an output from the direction detecting means.

(Operation) The homing guidance device of the present invention detects the intensity of the radio wave radiated from the sky or the ground received by the antenna during the radio wave emission stop period, and the radio wave intensity exceeds a predetermined value and becomes large. Then, it is detected that the direction of the directional axis of the antenna crosses the horizon, and as a result, the emission of radio waves for active homing is started. The radiant temperature is higher than the sky above the sky, so even during the period when the antenna does not emit radio waves and only receives it (hereinafter referred to as the passive reception period), the received radio field intensity of the antenna is that the directivity axis of the antenna points toward the sky. It is higher when the directional axis is facing the ground than when. This is for example MISKOLNIK “Radar Handbook” 197
As shown in 0, McGraw-Hill Inc., it is known that an object with an absolute temperature of zero degrees or more radiates a radio wave according to Rayleigh's equation, so the received power in passive reception is the equivalent temperature of the radiating object. Proportional to. For this reason, the equivalent temperature on the surface of the earth has a large value that differs by one digit or more from that of the sky regardless of the weather conditions. Therefore, when the directional axis of the antenna crosses the horizon, the received radio field intensity of the antenna increases rapidly. Therefore, in the present invention, the predicted value of the received radio wave intensity when the directional axis crosses the horizon is set to a threshold value (predetermined value), and when the received radio field intensity exceeds the threshold value, the direction of the directional axis of the antenna crosses the horizon line. This is detected, and as a result, the emission of radio waves for active homing is started. The device of the present invention thus determines when to start emitting radio waves, so that it begins to emit radio waves when the directional axis of the antenna traverses the horizon.

(Example) Next, an example is given and the present invention is explained in detail.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a view showing a flight path of a ground missile equipped with the embodiment of FIG. 1 and a direction of an aerial beam of the embodiment, and FIG. Two
It is a figure which shows the intensity | strength of all the received radio waves which enter into the antenna beam in the passive reception (reception which does not radiate an electric wave from an antenna) corresponding to the flight path of a figure. As shown in FIG. 2, the flight path of the missile 12 with respect to the target 13 on the earth 11 is conductive, so that the beam of the antenna is directed from the sky to the ground as it flies. In FIG. 2, a certain time when the directional axis of the aerial line (the central axis of the beam) is facing the sky is t ₁ , a time when it is facing the horizon is t ₂ , and a certain time is facing the ground. At t ₃ , the received radio wave intensity of the antenna in the passive reception is larger when the pointing axis is facing the ground than when the pointing axis is facing the sky, and therefore changes as shown in FIG. 3 with time. . Therefore, the received radio wave intensity changes abruptly near time t ₂ when the antenna directivity axis crosses the horizon. In this embodiment, when the received radio wave intensity exceeds a certain value (threshold value), it is considered that the directional axis of the antenna crosses the horizon, and the emission of the radio wave for active homing is started.

In the present invention, since the sky and the ground, which are radiating objects, are sufficiently larger than the antenna beam angle of the antenna provided in the missile, the received power is not related to the distance between the radiating object and the receiving point, and is therefore related to the flying height of the missile. Its application is wide because it can detect the difference between radio waves radiated from the sky and from the ground. In addition, since the high frequency band of the microwave band and millimeter waves are used in passive reception, there is no influence of ionospheric reflected waves.

Next, the specific configuration and operation of this embodiment will be described with reference to FIG. The present embodiment includes a seeker 1 and a discriminator 2. The seeker 1 operates in an active mode or a passive mode selected by switching. In active mode, active homing guidance is performed, and in passive mode, passive homing guidance is performed. In the initial period after the missile is launched, the missile flies without guidance, and during this non-guidance period, the present embodiment does not emit radio waves but only receives. During the period in which only this reception is performed, that is, in the passive reception period, the seeker 1 is in the passive mode, but the servo amplifier 8 does not operate and the antenna system 3 keeps the pointing axis directed toward the missile machine axis. The receiver 5 has a high receiving sensitivity because it is in the passive mode, and sends the signal 104 representing the received radio wave intensity to the discriminator 2. The discriminator 2 performs the passivation when the amplitude of the received radio wave intensity signal 104 exceeds a predetermined value during the passive reception period, that is, when the total power entering the antenna beam detected by the receiver 5 exceeds a certain value. -Activate the active switch 9 to start the transmission of the transmitter 4, and at the same time, switch the receiver 5 to the active reception, and set the operation of the seeker 1 to the active mode. The receiver 5 has a lower sensitivity in the active mode than in the passive mode.

When a missile guided by this embodiment is launched, the seeker 1
Has been in the state of passive reception from the beginning, and while the antenna beam is pointing to the sky, the received electric wave intensity is low as shown in FIG. 3, so the seeker 1 is still in the state of passive reception. Next, when the antenna beam is directed from the sky to the ground, the received radio wave intensity exceeds a predetermined threshold value, so the discriminator 2 detects that the antenna beam has crossed the horizon and sets the seeker 1 to the active mode. Start sending.

Seeker 1 tracks the target using the conical skiyan method.
The antenna system 3 includes an antenna and a drive device that drives the antenna in a target direction. The transmission / reception switcher 6 guides the transmission signal 112 of the receiver 4 to the antenna system 3, and guides the reception signal of the antenna as the signal 103 to the receiver 5 during the period when the transmission signal 112 is absent.
The angle detector 7 receives the output 105 of the receiver 5 and the antenna angle signal 102, and outputs an error angle signal 107. Error angle signal 107
Is supplied to the missile steering system and the servo amplifier 8.
The servo amplifier 8 power-amplifies the error angle signal 107 and supplies the antenna drive signal 108 to the antenna system 3. In this example,
When the target is searched for in the active mode, the target is tracked, and the distance between the missile and the target becomes equal to or less than a predetermined value, the passive mode is set. Therefore, the distance information 106 is supplied to the passive / active switch 9 as the distance information. Passive
In the passive mode, the active changeover device 9 outputs the signal 110.
Transmission of the transmitter 4 is stopped by the
Increase the sensitivity of. In the active mode, the switch 9 causes the transmitter 4 to start transmission by the signal 110,
The signal 111 reduces the sensitivity of the receiver 5.

In the present invention, after the missile has been launched, after it has sufficiently risen, the above-mentioned operation of detecting the missile crossing the horizon is started.

In the present embodiment, as is clear from the above description, when the antenna's directional axis crosses the horizon, it emits radio waves and starts active mode.Therefore, the guided missile is difficult to detect radio waves, and the ground target of active homing The search can be started at an appropriate time. Moreover, in this embodiment,
Since the discriminator 2 is simply added to the commonly used seeker 1, it is extremely inexpensive as compared with the conventionally used attitude sensor.

(Effects of the Invention) According to the present invention, as described above, it is possible to provide a cheap homing guidance device in which the guided missile is difficult to be detected by radio waves and the search for the ground target by active homing is started at an appropriate time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory view showing a flight path of an anti-ground missile equipped with the embodiment of FIG. 1 and an aerial beam direction of the embodiment, FIG. FIG. 4 is a diagram showing a received radio field intensity in the flight route shown in FIG. 2. 1 ... Seeker, 2 ... Discriminator, 3 ... Antenna system, 4 ...
Transmitter, 5 ... Receiver, 6 ... Transmission / reception switcher, 7 ... Angle detector, 8 ... Servo amplifier.

Claims (1)

[Claims] 1. A homing guide device that does not emit radio waves for active homing during the initial period of flight of a missile and starts the emission from the middle of the flight, in which the antenna received by the missile surrounds Detecting means for detecting the intensity of the radiated radio wave from the, the missile by detecting that the intensity of the radio wave has changed from a minute value corresponding to the radiated radio wave from the sky to a large value corresponding to the radiated radio wave from the ground A homing guide device comprising: direction detecting means for detecting that the direction of the directional axis of the object crosses the horizon; and radiation starting means for starting the radiation by the output from the direction detecting means.