JPH02285874A - Image signal output device for target extraction processing for image tracking system - Google Patents

Abstract

PURPOSE:To prevent waste time from being generated in scan conversion by performing the horizontal field scan of an optical system synchronizing with the vertical synchronizing signal of a television signal, and obtaining the perpendicular directional output of the optical system according to an address synchronized with the horizontal synchronizing signal of the television signal. CONSTITUTION:A scanner mirror 3 is scan-controlled so that the timing of the center of optical scan can correspond to that of the center of the perpendicular directional field in the television signal synchronizing with a scan synchronizing signal of NTSC system by a driving signal from a scan control circuit 14. The output of the detecting elements 8a of a detector 8 are amplified by video amplifiers 9-1-9-n, respectively, and are supplied to an analog multiplexer 10, and are converted to signals of (m) channels synchronizing with the horizontal synchronizing signal of NTSC system by the address from an address control circuit 13 at the multiplexer.

Description

[Detailed Description of the Invention] [Summary] An image tracking system that extracts a target from an image acquired by an image sensor and drives a gimbal of 1811 centimeters in order to continue capturing the target, eliminates wasted time caused by scan conversion. The purpose of the present invention is to eliminate the occurrence of horizontal synchronization and to configure a high-performance image tracking loop. It is constituted by signal multiplexing means for aligning the center of the output timing of each detection element of the detector with the synchronization center timing.

[Industrial application field]

The present invention relates to an image tracking system that extracts a target from an image acquired by a wt image carrier sensor and drives a gimbal of an m image sensor to continue capturing the target.

Such an image tracking system includes a carrier image sensor mounted on, for example, an aircraft, tracks a target on the ground, and notifies a ground station or the like of the target position. Here, due to the characteristics of the system, the longer the delay time or dead time of each element constituting the tracking loop, the smaller the loop gain must be, leading to an increase in tracking error. For this reason, it is necessary to reduce elements with delay time and waste time as much as possible, and to shorten the delay time and waste time of each element.

[Conventional technology]

When trying to use a general-purpose digital image processing circuit as a target extraction processing circuit, it is designed to input in the Japanese Standard Television System (NTSC system), and a linear image processing circuit that captures images in a different format. - When applying a parallel scanning type image carrier sensor using an array multi-element detector, a scan conversion circuit is used to perform scan conversion on the INN rough format of the am sensor to convert it into an NTSC format. That is, by using a scan conversion circuit consisting of field memories for two fields and their address control circuits, while image data of one field is read out from one field memory in the NTSC format, data of the other field is read out. Ill rough format is written to the other field memory.

The image data scan-converted into the NTSC format in this way is supplied to the image processing circuit (target extraction processing circuit) as image data of the target extraction processing circuit, where it is processed as an image, and the target is extracted. While driving and controlling the gimbal of the glide image sensor that continues to capture the image data, the image data is supplied to a monitor television receiver or the like for monitoring.

[Problem to be solved by the invention]

As mentioned above, the conventional system performs scan conversion using field memory, so there is a dead time of one field period from imaging to outputting the image signal, which poses the problem of not being able to track images with high performance. there were.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image signal output circuit for target extraction processing that eliminates wasted time caused by scan conversion and can configure a high-performance image tracking loop.

[Means to solve the problem]

FIG. 1 shows a diagram of the principle of the present invention. In the figure, 20 is a linear array multi-element detector in which a plurality of detection elements 20a are arranged in parallel in the vertical direction. Reference numeral 21 denotes a horizontal visual field scanning means, which aligns the horizontal visual field center timing of the detector 20 with the vertical synchronization center timing in the television signal.

22 is a signal multiplexing means which multiplexes each detection element 20a of the detector 20 at the center timing of horizontal synchronization in the television signal.
Align the center of the output timing.

[Effect]

By aligning the vertical center timing of the optical system field of view with the horizontal synchronization center timing in the television signal, and by aligning the horizontal direction center timing of the optical system field of view with the vertical synchronization center timing in the television signal,
18! ! The format can be converted to a television signal format, and image data for target extraction processing can be obtained. Since the horizontal and vertical relationships are reversed, the vertical signal is used to drive the gimbal's horizontal axis, and the horizontal signal is used to drive the gimbal's vertical axis.

In this way, Il without using field memory
Since the L format is converted to the television signal format, there is no wasted FfI time between image capture and output of the image signal, and there is no deterioration in tracking performance, compared to conventional systems that write to and read from field memory. .

〔Example〕

FIG. 2 shows a block diagram for implementing the invention. In the figure, 1 is the frame corresponding to the R@ scene, and EV
The EN field is shown as la, and the ODD field is shown as 1b. 2 is a condensing optical system that condenses the light flux from the scene. 3 is a scanner mirror which is driven by a scanner driver 4 in synchronization with the vertical synchronization signal of the television signal;
Reference numeral 5 denotes an interlace mirror, which is driven by an interlace driver 6 and switches EVENloDD of the field. Reference numeral 7 denotes an imaging optical system which forms an image of the scanned light beam onto a detection element. 8 is a linear array multi-element detector, which includes, for example, 120 (n) detection elements 8a. 9
-1 to 9-o are n-channel video amplifiers that amplify the output signals of each sensing element to a level required for subsequent processing. 10 is an analog multiplexer and n-channel video amplifiers 9-1 to 9. Each output is multiplexed into m (<n) channels (m is, for example, 8) of analog signals. 11
is an AD converter which converts the output of the analog multiplexer 10 into digital data. 12 is digital
The multiplexer further multiplexes the output of the AD converter 11 into one channel of digital data. If possible in terms of operating speed, it is also possible to multiplex into one channel using the analog multiplexer 10 and omit the digital multiplexer 12. Reference numeral 13 denotes an address control circuit that controls analog multiplexers 10. AD converter 11, digital multiplexer 12. Scanner driver 4.
A control address and a clock are generated for the scan control circuit 14 that drives and controls the interlace driver 6. 14
is a scan control circuit that generates drive signals to the scanner driver 4 and interlace driver 6 according to the scan synchronization signal from the address 1lJi11 circuit 13, and controls the scanner mirror 3 and interlace mirror 5 with the required waveform. Make it work. 15 is a synchronization signal generation circuit, which is a digital
An NTSC synchronization signal is generated that relates the output of multiplexer 10 to the position on the screen.

16 is an OA converter, and a digital multiplexer 12
The output of is analog data. Reference numeral 17 denotes an image processing circuit, which is supplied with image data for target extraction processing taken out from the digital multiplexer 12, extracts a target by digital image processing, and drives the gimbal of the mm sensor to continue capturing the target. The image processing circuit 17 is a general-purpose digital image processor. 1
A monitor television receiver 8 displays the target position on a monitor.

In addition, in the conventional example, a field memory for two fields is provided between the digital multiplexer 12 and the image processing circuit 17 (the other circuit configuration is almost the same as that in Fig. 2 (the part a is different). However, in the present invention, such a field memory is not provided.

Next, the operation of the present invention will be explained along with the operation timing chart shown in FIG. 3.

The scanner mirror 3 is driven by a drive signal from the scan control circuit 14 to perform an NTSC scan J81 period signal 9 (see Fig. 3 (A).
)), scanning 11JIII is performed such that the timing of the optical scanning center corresponds to the timing of the vertical visual field center in the television signal, as shown in FIG. 3(B). Specifically, as shown in FIG. 4, the vertical center position B(φ) of the visual field in the television signal is in the horizontal direction of the optical scanning visual field, and the interlace mirror 5 is moved by the drive signal from the scanning control circuit 14. As shown in FIG. 3(C) in synchronization with the scanning synchronization signal of the N'r SC method (FIG. 3(A)), the odd (ODD) field and even (EVEN) field are
Controlled to switch fields.

An effective scanning range is set before and after the scanning center by the scanner mirror 3 and interlace mirror 5, and interlace operation is performed during the other periods.

The output of each detection element 8a of the detector 8 is amplified by video amplifiers 9-1 to 9-, respectively, to produce the signal shown in FIG. NTS by the address from the control circuit 13
The signal is converted into an m-channel signal in synchronization with the horizontal synchronizing signal of the C system (FIG. 3(E)). Here, in reality, the number of sensing elements 8a is n-120, and the analog multiplexer 10
The number of channels is m=B, but to simplify the explanation, it is assumed to be n-16 and m-4.

Since the outputs of n-16 video amplifiers (9-4 to 9-0) are converted into m-channel parallel signals by the analog multiplexer (10), as shown in FIG.
The signals for every other channel (1<=n/m=4) are multiplexed so that they are distributed in the same number after the timing of the center of the horizontal field of view in the Nrsc television signal.

That is, as shown in FIG. 3 (F) and FIG.
h(1+m), ch(1+ (L/2>・m>.

Each output of channel (1+ (t-1)m) is arranged in parallel, and analog multiplexer (10
) is the horizontal synchronizing signal Ha, -, Hb
Sensing element ch (m) for each , , , .

ch(2rn), ch(3m), ch(m+ <t −
1) Each output of m>=ch(L-m)=-ch(n) is arranged in parallel. In this way, n-channel video amplifiers 9-1 to 9. Each output is multiplexed into m-channel analog signals for each horizontal synchronization signal of the NTSC television signal, and by repeating this in odd and even fields, the field of view in the NTSC television signal is This is effectively equivalent to scanning all the data.

The output of m channel of analog multiplexer 1o is A
[) is supplied to the converter 11, where the address tlQ11
The data is converted into digital data by the clock from the 1 circuit 13, and is supplied to the digital multiplexer 12, where it is further multiplexed by the 7 addresses from the address system W circuit 13, resulting in 1 channel of digital data (see FIG. 3). G)). The data obtained in this way is determined in the vertical direction of the optical field at the horizontal synchronization center timing of the NTSC television signal ((A), (B), ... (C) in Figure 4 (A>)). Center timing (Figure 4 (B)
)'s (a), (b), ... (c)) can be combined,
This is a signal in which the horizontal scanning center timing of the optical field is aligned with the vertical synchronization center timing (φ in Figure 4 (A)) of the NTSC television signal, and as a result, the carrier format is the NTSC television signal. It can be regarded as a signal converted into a format.

The output of the digital multiplexer 12 is the DA converter 1
After being converted into an analog signal at step 6, it is supplied to a television receiver 18 and displayed on a monitor, while the output of the digital multiplexer 12 is supplied to an image processing circuit 17 for digital image processing, and the target position d is is calculated and gimbal drive control is performed. Therefore, as in the conventional example, using two field memories, the a-image data of one field is read out from one field memory in the NTSC format, and during this time the other field is read into the other field memory in the imaging format. Since such conversion is not required, there is no wasted time from the image carrying image to the output of the image signal, and there is no deterioration in tracking performance.

Note that since the imaging format/NTSC television signal format conversion of the present invention is performed as described above, the horizontal and vertical relationships are reversed. Therefore, the image processing circuit 17 and the television receiver 1B are configured to perform horizontal/vertical conversion. For example, in the image processing circuit 17, a signal input as a vertical coordinate is used to generate a drive signal for an axis corresponding to the horizontal direction of the gimbal, and a signal input as a horizontal coordinate is used to generate a drive signal for an axis corresponding to the vertical direction of the gimbal. This is used to generate drive signals for the axes.

(Effects of the Invention) As explained above, according to the present invention, the horizontal field of view of the optical system is scanned in synchronization with the vertical synchronization signal of the television signal, and according to the address synchronized with the horizontal synchronization signal of the television signal. Because the optical system is configured to obtain a vertical output, even when using a linear array multi-element detector with a carrier format different from the television signal format, there is no wasted time during scan conversion, and two field memories can be used. It is possible to perform image tracking with higher performance than in the conventional example in which conversion is performed using the following methods.

[Brief explanation of drawings]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a diagram of the principle of the present invention, Fig. 2 is a block diagram for implementing the present invention;
The figure is an operation timing chart of the present invention, Figure 4 is a diagram explaining the relationship between the synchronization center and the center of optical field of view in a television signal, and Figure 5 is a diagram explaining the conversion operation from n channel to m channel. . 9-1+9-o is a video amplifier, 10 is an analog multiplexer, 11 is an AD converter, 12 is a digital multiplexer, 13 is an address control circuit, 14 is a scan control circuit, 15 is a synchronization signal generation circuit, 17 is an image 21 is a horizontal field of view scanning means; and 22 is a signal multiplexing means.

Claims (1)

[Claims] The field of view is scanned in the horizontal direction, and a plurality of detection elements (20a
) is vertically arranged in parallel with an image sensor using linear array multi-element detectors (20). an image tracking system that drives a horizontal visual field scanning means (21) that aligns the horizontal visual field center timing of the detector (20) with the vertical synchronization center timing in the television signal; An image signal output device for target extraction processing in an image tracking system, comprising a signal multiplexing means (22) for aligning the center of the output timing of each detection element (20a) of the detector (20) with the center timing.