JPH0517682Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a target tracking device for a flying object that performs, for example, proportional navigation and tracks a target.

[Technical background of the invention]

FIG. 1 is a diagram showing a tracking situation of a flying object tracking a target using proportional navigation. In the figure, 11 is a flying object and 12 is a target. X is flying object 1
1, and Y is the optical axis of a target detection section provided on the flying object 11. L is an expected angle between the flight direction of the flying object 11 and the optical axis Y, and G is an angle between the aircraft axis X and the optical axis Y. V _M is the projectile velocity. Z is the flight path of target 12.

A flying object that performs proportional navigation has conventionally had a target tracking device as shown in FIG. 2, and has tracked the target 12 according to a guidance law such as the following equation (1).

γ _M =N・λ...(1) Here, γ _M : Projectile path angle change rate N : Navigation gain λ : Line of sight angle change rate In FIG. 2, 13 is a target detection unit, and for example, Detects targets using infrared rays. Then, the eye gaze angle change rate λ is obtained based on the detection output. 14
is a path angle change rate detection unit, which calculates the path angle change rate γ _M by calculating the above equation (1). Reference numeral 15 denotes an aircraft characteristics compensator, which corrects the path angle change rate γ _M obtained by the path angle change rate detector 14 to match the aircraft characteristics.

In addition, in order to succeed in proportional navigation, the effective navigation constant N′ as shown by the following equation (2) must be within a certain range (the practical range required for the projectile to hit the target using proportional navigation). range).

N′=N・cosL・V _M /V _C …(2) Here, V _C : Approach speed between the target and the flying object Regarding the setting range of this effective navigational number N′,
"Principle of Guided Missile Design" series (1960, D.VAN NOSTRAND
“Systems” by COMPANY, INC.
Preliminary Design” (written by Joseph J. Jager)
The details are explained from pages 188 to 200.

According to the above literature, when the target does not turn but moves in a straight line, the turning acceleration of the projectile (missile) necessary for it to hit the target is calculated for various values of N′. (Reference No.
(See FIG. 5-6 on page 193), when N' is less than 2, the turning acceleration of the projectile required just before hitting diverges to infinity, and the projectile does not hit the target.

In addition, when the target turns with a constant acceleration, the turning acceleration of the projectile necessary for the projectile to hit the target is calculated for various values of N' (Reference, p. 198, FIG. 5-7 ), when N' is 3 or less, the turning acceleration of the projectile required just before hitting tends to increase rapidly.

From the above, it can be said that it is a practical requirement that N' be 3 or more.

However, in reality, if N' is 3 or more, it is not possible to set the value as large as desired. In other words, if N′ is set to too large a value, the control signal for turning the flying object will be excessively amplified, and the influence of noise superimposed on the signal will become noticeable, which will actually reduce the accuracy of the shot. This will result in

Therefore, the practical setting range of N' has not only a lower limit value but also an upper limit value. From conventional experience, it is necessary to set N' in the range of 3 to 6 (pointed out on the bottom line of page 192 of the document).

[Problems with background technology]

However, in the case of the above configuration, the following problems occurred. That is, among the factors N, cosL, V _M , and V _C that determine the effective navigation coefficients, N is a constant determined at the design stage, but cosL, V _M , and V _C change depending on the situation at the time of interception. In this way, the effective navigational number
Since N′ includes many variables, it may not fall within a certain predetermined range depending on the situation at the time of the interception. Therefore, the effective navigational law number
In order to keep N′ within a certain range, cosL,
The navigation gain N must be reduced in anticipation of changes in V _M and V _C . As a result, with conventional target tracking devices, there are significant restrictions on the degree of freedom in design and the setting of the range that can be tracked.

[Purpose of invention]

This invention was made in order to cope with the above-mentioned circumstances, and the purpose is to provide a target tracking device for a flying object that can greatly expand the degree of freedom in design and the range in which tracking can be performed.

[Summary of the idea]

This idea takes advantage of the fact that the angle between the optical axis of the target detection means and the aircraft axis is approximately equal to the anticipation angle, and uses a certain constant divided by the cosine of the above angle as the navigation gain, rather than a constant. use it,
It is constructed so that the anticipation angle can be removed from the variation factor of the effective navigation constant N'.

[Example of idea]

Hereinafter, one embodiment of this invention will be described in detail with reference to FIG.

In FIG. 3, 21 is a target detection section, which detects a target using, for example, infrared rays. Then, according to this detection result, the line of sight change rate λ is obtained, and the angle G between the optical axis Y and the aircraft axis X for detecting the target is obtained. 22 is a path angle change rate detection section. This path angle change rate detection section 22 is a target detection section 2.
The path angle change rate γ _M is obtained by taking the cosine of the angle G obtained in step 1, dividing it by a constant A, and multiplying it by the line of sight change rate λ as a navigation gain. Reference numeral 23 denotes an aircraft characteristics compensation unit, which, like the aircraft characteristics compensation unit ₂₃ shown in FIG. to correct.

As detailed above, according to this embodiment, the angle G formed between the optical axis Y and the aircraft axis X for target detection is detected, and the value obtained by dividing a certain constant A by the cosine of this angle G is set as the target. The navigation gain should be multiplied by the line-of-sight angle change rate λ. According to such a configuration, the effective navigational constant N' is N'=A/cosG·cosL·V _M /V _C (3). Here, since the angle G and the expected angle L are almost equal, cosG≒cosL, and the effective navigational constant N' becomes N'≒A·V _M /V _C (4).

As is clear from equation (4), in this embodiment, the factor of cosL is removed from among the factors that determine the effective navigational constant N', and the only factors that change it are V _M and V _C. Therefore, by removing the cosL factor, it becomes easier to keep the effective navigational constant N' within a certain range, and the degree of freedom in the design of the tracking device is increased.
The tracking range can be greatly expanded.

[Effect of idea]

As described above, according to this invention, it is possible to eliminate the influence of fluctuations in the anticipation angle on the effective navigation constant, thereby providing a target tracking device for a flying object that can increase the degree of freedom in design and expand the range of tracking possible. be able to.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a flying object tracking situation, Fig. 2 is a circuit diagram showing a conventional flying object tracking device, and Fig. 3 is a circuit diagram showing an embodiment of a flying object tracking device according to this invention. It is. 21...Target detection section, 22...Route angle change rate detection section, 23...Airframe characteristics compensation section.

Claims (1)

[Scope of Claim for Utility Model Registration] A target tracking device for a flying object that tracks a flying object to a target by proportional navigation based on effective navigational constants, which detects the target, obtains a rate of change in the line of sight angle from the detection result, and A target detection means for obtaining the angle between the optical axis and the aircraft axis for target detection, and a navigation gain obtained by dividing a certain constant by the cosine of the angle obtained by the target detection means, and the change in the line of sight angle. a path angle change rate detection means for obtaining a path angle change rate by multiplying the rate by multiplying the effective navigation constant by N', a certain constant by A, the velocity of the flying object by V _M , and the approach between the target and the flying object. When the velocity is V _C , from the relational expression N'=A・V _M /V _C , it is necessary to make sure that the effective navigational constant falls within the practical range necessary for the projectile to hit the target using proportional navigation. A target tracking device for a flying object, characterized in that a certain constant is determined.