JPH0372913B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for guiding and controlling flying objects such as rockets and missiles.

Proportional navigation, which will be described below, is a well-known conventional guidance control method of this type. In addition, although the number is small, pure tracking (Pure tracking)
Pursuit) There is navigation. The former is better when the target is moving quickly, and the latter can also track relatively slow targets, which has the advantage of being simple in configuration. Although the present invention can be applied to both of these navigation methods, it is especially effective when used in combination with the latter method, which is used when targeting slow targets.

For simplicity, explanation will be given in a two-dimensional plane. In Figure 1, let _n and _t be the velocity vectors of flying object 1 and target 2, respectively. Flying body 1 and target 2
The line 4 connecting these is called the line of sight.
A reference line 3 fixed in an inertial coordinate system is taken, and the path angle of the flying object 1 and the angle of the line of sight 4 measured from this line are Υ and σ, respectively. The flying body 1 uses air force, thrust, etc. to increase the acceleration a perpendicular to the direction of travel.
is generated to track the target 2, but in proportional navigation, this acceleration is controlled so that a = N _e · V _c · σ 〓. Here, V _c is the approach speed of the flying object 1 and the target 2, and N _e is what is called the effective navigation coefficient. As a result, the path angle change rate γ of the flying object 1 is proportional to σ, and as long as this relationship is maintained, the flying object 1 will always collide with the target 2. In order to implement this method in hardware, two sensors are required to obtain σ measured in the inertial coordinate system.
When using a sensor mounted on an axis gimbal or fixed to the machine axis, the following processing is required. That is, the second
In the figure, the angle θ between the reference line 3 and the machine axis line 5 is defined as a pitch angle, and the angle between the machine axis line 5 and the line of sight 4 is defined as ε _y . The signal observed by the sensor fixed to the machine shaft is ε _y
Therefore, in order to obtain δ from this, it is necessary to measure the pitch angular velocity θ〓 using a rate gyro, etc., integrate this to obtain θ, add it to ε _y , and calculate δ. .

In the pure tracking method, a sensor fixed to the above-mentioned axis is often used. In this case, by feeding back a PD (proportional + differential) signal such as K ₁ ε _y +K ₂ ε 〓 _y as a pitch control signal, the nose of flying object 1 is always pointed in the direction of target 2 and tracking is performed. I will continue to do so. Although this navigation method does not use a gimbal-mounted sensor and does not require a rate gyroscope, the pitch movement of the flying object 1 and the sensor signal are coupled, resulting in poor control. To compensate for this drawback, there is a method in which control is performed by measuring the angle between the wind axis (in the direction of _n ) and the line of sight 4 instead of the machine axis 5. For example, Texas Instruments)
Paveway (Texas Instruments) has a wind direction probe attached to the nose of the aircraft, and a sensor attached to this measures the above angle and provides guidance using a pure tracking method. In this case, even if the attitude of the aircraft changes, the direction of _n does not change abruptly, so coupling between the pitch motion and the sensor signal is eliminated, resulting in highly accurate guidance control.

As described above, all of the conventional methods require complicated hardware configurations, such as using a gimbal-mounted sensor, a wind direction probe-mounted sensor, or a rate gyro.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, the present invention aims to provide an apparatus that uses a fixed axis sensor and performs accurate guidance only by simple signal processing without using a rate gyro or the like.

The present invention provides a method for guiding and controlling a flying object by processing, in a processing circuit, an angle signal _{ε y} between the line of sight and an aircraft axis obtained by a sensor attached to the flying object. Angular signal to be processed ε _y
If the angle signal ε^ _y obtained by filtering the angle signal ε _y beforehand with an extremely low frequency filter and smoothing it with a noise filter exceeds a predetermined threshold value ±ε _n , the gain K of the processing circuit is set to a predetermined large value k _a If the angle signal ε^ _y falls within ±(ε _n −△ε) [△ε is a predetermined small value], the gain K is returned to the original small value K _b and the flying object is The gist of this invention is a method for guiding and controlling a flying object, which is characterized by guiding and controlling a flying object.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 shows an example of signal processing in a conventional pure tracking system. That is, in the figure, ε _y is the angle signal from the target 2 machine axis obtained from the machine axis fixed sensor, τ _H is the time constant of the approximate differential circuit, K ₁ and K ₂ are the gains for ε _y and ε〓 _y, respectively, and S _y is This is the obtained actuator drive signal. It has already been mentioned that in this example, since ε _y couples with the pitch motion θ of the flying object 1, the control may not be performed well. In FIG. 5, the sensor signal is first passed through a low-pass filter 7 with a large time constant τ so as to narrow the band to an extremely low frequency, and this signal is processed in the same manner as in FIG. Since the frequency of the attitude motion of the flying object 1 is relatively fast, this processing can reduce its influence. However, on the other hand, it is not possible to follow the fast movement of the target 2, and there is a possibility that the target 2 may be out of the field of view of the sensor. Therefore, as shown in the figure, when the signal ε^ _y obtained by smoothing the signal ε _y with the noise filter 8 exceeds a certain threshold value ±ε _n , the gain switching element 10 is switched and the gain K
Switch to a large value K _a . The signal ε^ _y is ±(ε _n −△
Once inside ε), set K to the original small value again.
Return to K _b . In the case of a slowly moving target, the rate of change of the eye angle σ is small until just before the collision, so
By using the signal processing device as described above,
It does not require complicated hardware and can track targets with higher precision than conventional pure tracking methods.

In the above embodiment, a case was described in which the pure tracking method was used in combination, but this can also be used in combination with proportional navigation. This tracking method can also be applied to navigation when an airplane approaches a target. Although FIG. 5 shows an example of 1/(1+τS) ² as an extremely low band filter, this may be any suitable filter that narrows down the band to an extremely low level.

As described above, according to the present invention, since a sensor fixed to the aircraft axis is used and the coupling effect of the aircraft attitude movement is removed only by signal processing,
This has the effect of not requiring a rate gyro or the like, making the device inexpensive, or providing a highly accurate guidance control system.

[Brief explanation of drawings]

Figure 1 is a diagram of the relationship between the flying object and the target when tracking the target using proportional navigation, Figure 2 is a diagram of the relationship between the flying object and the target when tracking the target using pure tracking navigation, and Figure 3 is a diagram of the relationship between the flying object and the target when tracking the target using proportional navigation. Show the image. FIG. 4 is an example of a signal processing system block diagram when conventional pure tracking navigation is used, and FIG. 5 is a signal processing system block diagram according to an embodiment of the present invention. Note that the same reference numerals in the figures indicate the same or equivalent parts. 1... Flying object, 2... Target, 3... Reference line, 4... Line of sight, 5... Axis line, 6... Sensor screen, 7... Very low band filter, 8... Noise filter, 9... Bang bang element with hysteresis, 1
0...Gain switching element.

Claims (1)

[Claims] 1. A method for guiding and controlling a flying object by processing, in a processing circuit, an angle signal _{ε y} between the line of sight and the aircraft axis obtained by a sensor attached to the flying object, The angle signal ε _y to be processed by the processing circuit is filtered in advance with an extremely low frequency filter, and if the angle signal ε^ _y obtained by smoothing the angle signal ε _y with a noise filter exceeds a predetermined threshold value ±ε _n , the processing circuit The gain K of is switched to a predetermined large value k _a , and the angle signal ε^ _y becomes ±
(ε _n −△ε) [△ε is a predetermined small value], the flying body is guided and controlled by returning the gain K to the original small value K _b guidance control method.