JPS6318281A - Target tracking apparatus - Google Patents

Abstract

PURPOSE:To enable the tracking of a target with a high accuracy regardless of changes in the relative distance from the target, by detecting an image of the target with a plurality of detection elements to generate a target tacking error signal with a signal processing of output signals of the detection element. CONSTITUTION:By the application of multiple elements, a detector 13 is made possible to detect a long-range target with high resolutions. A signal processing system 14 is provided with a resolutions control section 145, which 145 receives the input of a target tracking signal as obtained with a tracking error calculating section 144 to judge the size thereof. When the target tracking signal is below a set value, a long-range target is identified and a reading section 141 is controlled to read a full detection element, thereby accomplishing high resolutions. When the target is above the set value, a short-range target is identified and the frequency of reading detection element signals is limited to one-fourth of all the detection elements to increase the tracking angular velocity with a higher signal processing speed of a signal processing system 14. This always enables accurate tracking of a target not depending on the relative distance from the target thereby assuring a precision guidance when this apparatus is carried on a missile or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a target tracking VR system mounted on, for example, an image-guided missile.

(Prior art) As is well known, the image guidance method, which detects and tracks the target as an image rather than a point, has a large amount of information from the target and its background, so it has excellent interference resistance and is capable of precise guidance. . A target tracking device constituting this image guidance system is generally constructed as shown in FIG.

That is, this target tracking device uses an optical system 11 to image the target A on a detector 13 in which a plurality of detection elements 12 are arranged two-dimensionally, as shown in FIG. 5(a), for example. Then, in the signal processing system 14, the reading unit 141 reads the sensing element signal from the detector 13, the level determining unit 142 determines whether the sensing element signal exceeds the set level, and the center of gravity calculation unit 143 determines whether the sensing element signal exceeds the set level. The center of gravity of the target image is calculated based on the signal that exceeds The tracking error signal is sent to the drive system 15 as a target tracking signal to direct the optical system 11 and the detector 13 in the target direction. If such a target tracking device is mounted on a missile and the steering control device etc. is controlled by the target tracking signal,
It is possible to accurately guide the missile towards the target.

By the way, when the target tracking device is used for detecting and tracking a long-distance target, the target image becomes small and becomes a dot as shown in FIG. 5(b). In this case, target detection becomes difficult and separation from the background becomes impossible. Therefore, in order to detect and track a long-distance target, it is necessary to capture the target as an image rather than a point. As such a detection means, it is conceivable to increase the resolution by, for example, zooming the optical system 11 or increasing the number of elements in the detector 13, but there are many restrictions such as size and mass when mounting the missile, and reliability is limited. It is inappropriate to employ a zoom structure with missing mechanical movable parts, so it is desirable to have a multi-element detector for higher resolution.

On the other hand, one of the important performances of a target tracking device is tracking angular velocity capability. For example, a missile that intercepts an air-to-air target is required to have high tracking angular velocity capability because the relative motion with the target is very large.

What determines this tracking angular velocity capability is the signal processing speed of the signal processing system in the case of eight-tailed targeting (target of both image guidance method).
This signal processing speed becomes slower as the number of sensing elements in the detector increases.Therefore, when increasing the number of sensing elements in the detector and capturing a long-range target as an image with high resolution for precise guidance, The tracking angular velocity capability decreases, making it impossible to accurately guide the target as it approaches the target.Conversely, if the number of sensing elements in the detector is reduced and the tracking angular velocity capability is increased, the resolution becomes low and it becomes difficult to guide the target at long distances. Precise guidance becomes impossible.

(Problems to be Solved by the Invention) This invention improves the problem in which the tracking ability of conventional devices deteriorates significantly when the relative distance to the target changes, and detects long-range targets with high resolution. It is an object of the present invention to provide a target tracking device that can increase the signal processing speed, provide high tracking angular velocity capability as needed, and enable highly accurate tracking even when the relative distance to the target changes. purpose.

[Structure of the invention] (Means and effects for solving the problem) That is, the target tracking device according to the present invention detects a target image with a plurality of detection elements, and performs signal processing on the output signal of each detection element. A target tracking error signal is generated and the number of output signals of the plurality of detection elements is controlled to increase or decrease the image resolution.

(Minoura Example) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. However, in FIG. 1, the same parts as in FIG. 4 are designated by the same reference numerals, and only the different parts will be described here.

FIG. 1 shows a configuration in which the present invention is applied to the target tracking device shown in FIG. 4. That is, the detector 13 used here has a larger number of elements and can detect a long-range target with high resolution.

On the other hand, the signal processing system 14 is provided with a resolution control section 145. This resolution control unit 145 inputs the target tracking signal obtained by the tracking error calculation unit 144, determines the magnitude of this target tracking signal, and when the magnitude of the target tracking signal is equal to or less than a set value, the resolution control unit 145 outputs the readout unit 141 for all detection elements. In order to read out signals, the number of read signals of the sensing elements is controlled to be limited to 1/4 of the total number of sensing elements when the value exceeds a set value.

That is, in the case of missiles, etc., high tracking angular velocity capability is required during final guidance when the relative distance to target A becomes small. At this time, since the target image is relatively large, there is no problem even if the number of sensing elements to be read out is reduced to 1/4 of the total number of sensing elements, for example every other row or every other column.

Therefore, in this target tracking device, when the target is far away, the target image is small and the moving angular velocity is relatively low, so the target tracking signal is small, and as the target approaches, the target image becomes larger and moves. Taking advantage of the fact that the target tracking signal increases as the angular velocity increases, when the target tracking signal is below the set value, it is determined that the target is a long distance target and all sensing element signals are read out. As shown in a), when the target is higher than the set value, it is determined that it is a short-range target and the number of sensing element signal readouts is calculated as shown in Figure 2 (b).
), the signal processing speed of the signal processing system 14 is increased, and the tracking angular velocity is increased.

Therefore, the target tracking device configured as described above has high resolution for long-distance targets where the target image becomes small, and as the target approaches and the target image becomes large, the signal processing speed increases and the tracking angular velocity ability increases. Since the height is high, the target can always be accurately tracked regardless of the relative distance to the target, and when mounted on a missile or the like, precise guidance is always possible.

Note that this invention is not limited to the above embodiments.

For example, as described above, the number of readout of sensing element signals is
As shown in the figure, the control may be performed stepwise or transiently depending on the moving angular velocity of the target. The resolution control unit 145 also controls the area of the target image (level determination unit 14
The control may be performed based on the distance to the target, etc.) or the distance to the target. Alternatively, the detector 13 may be installed directly to limit the number of sensing element signals output to the signal processing system 14, or the output signals of a plurality of adjacent sensing elements may be summed to form a unit sensing element. It is also possible to reduce the number of signals to be processed. In addition, various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, according to the present invention, a long-range target can be detected with high resolution, the signal processing speed can be increased, and high tracking angular velocity capability can be obtained as required. is,
It is possible to provide a target tracking device that can track with high accuracy even if the relative distance to the target changes.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of a target tracking device according to the present invention, Fig. 2 is a pattern diagram showing a simulated target image captured by a detector of the same embodiment, and Fig. 3 is a block diagram showing an embodiment of the target tracking device according to the present invention. 4 is a block configuration diagram showing the configuration of a conventional target tracking device, and FIG. 5 is a simulation of a target image captured by a detector of a conventional target tracking device. FIG. DESCRIPTION OF SYMBOLS 11... Optical system, 12... Detector, 13... Detection element, 14... Signal processing system, 141... Reading part,
142... Level determination section, 143... Center of gravity calculation section,
144...Tracking error calculation unit, 145...Resolution control unit, 15...Drive system, A...Target.

Claims (1)

[Claims] a detection means configured with a plurality of detection elements to detect a target image; a signal processing means to which an output signal of the detection means is supplied, processes the signal and outputs a target tracking error signal; and a signal processing means from the detection means to the signal processing means. A target tracking device comprising: control means for increasing or decreasing image resolution by controlling the number of signals supplied.