DE2842684A1 - DEVICE FOR DETECTING AND TRACKING A GOAL - Google Patents

Description

HH 7S / O3 - 5 -

A Fa bent-Verwaltungs-G .m.b.H. 6000 li'rankfurt / Main? 0, 'fheodor-otern-Kai 1

"Device for recognizing and tracking a target"

The invention relates to a device according to the Features of the preamble of the main claim.

Target tracking and image processing systems exist below among other things from a stabilized observation device for recording from opto-electronic or thermal radiation s sensitive Image sensors, an actual target tracking or image processing computer and a device for image display (Monitor).

There are known facilities in which optical and / or electronic tools e.g. ß. one target mark superimposed in a television picture or paraxially via a target mark projector projected into the beam path of a JJirektsic ^ t observation device will.

They are target tracking systems, so-called 'fracking devices' known to work nacfi a contrast tracking principle. With this principle, the one recorded by the observation device The scene is divided into light or dark areas in such a way that, for example, all light areas are the target, all dark areas can be seen as a background (or vice versa). As a tracking reference point, the surface can be used as a target recognized bright area calculated, in a different type of execution

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the location einor light / dark edge "may be determined (Dd-OS 25 47 79s) With a movement d ^a s target a storage signal to a servo is;. / ^ t supplied n, which effects an adjustment de3 Heobaohtungsgerätes corresponding to the deviation signal?. Known designs of such tracking systems are also heads with quadrant detectors or certain television tracking devices. All these devices have in common the use of the information "contrast of the target against the background", which, for example, leads to a flight object being easily tracked in this way can, since it generally appears dark in front of a background with audible contrast, whereas such a device fails when a target with medium gray values is to be pursued in front of a strongly structured background.

Ks are verfolgungseinrichtungeil known target which evaluate a part of the structure information of the objective pursued loine known iiinric ^ tung operates nao "^ an optical method in which a ürts Fourier component of the target on i ^ rs P ^ ase opposite the shifted target to a The servo system regulates the observation device to a laterally constant phase position. However, if no actual storage of the target structure takes place, it is impossible, for example, to find a target once it has been lost. Further methods (D ^ -PA P 25 O ^ 536.7) use a digital target memory which does not know this disadvantage and which evaluates the entire structural information of the target.

It is of considerable fun for target tracking facilities Meaning, the target memory at sic> < strongly twisting, approaching or due to internal structural changes

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transforming goals ~ u update. Un to realize this, are the 08 riöglicVikeit the 1C0 / o Auffrisc ^v ens of Zielspeic ^v ers.

Furthermore, ^v at the practical h'ri'a ^ rung "cleans at Zielverfolgungseinrleitungen as £ se ^v r""-äufig the <:. iel completely odor t ^ ilv .'- aise may be hidden. For this reason, must ^ iriric be ^v dunk voi ^ -anaen that bridge this concealment periods in large ieuerleiteinrichtungen are Ba ^ altungen ndaten-Extrapo-iationB-rfe ^ called Prädiktionsrec'bner known.

It is also known to give system information on other screens in the case of extensive fire control systems ViIc ¹ H ti ge ^ - or use the usual operating mode representations (indicator lamps, Oat en ii Gp lays, etc.) ¹ JU.

This is where the invention comes in, which is the object of a track i'inriclntung to create the auc> for ground targets highly textured background as many tracking situations GEREC ^v t vjird and optimal interaction between operator and instrument guaranteed.

To solve this problem are in the characterizing part of the main claim suggested features.

The device according to the iCrfindung has components that

a. include intelligent target memory learning processes,

b. Can safely bridge times of target obscuration and

c. offer as many systemspezifisc ^v e and date information ant ^ ^ ropotec NISC ¹ "favorable.

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Developments oas ürfindiuigsgedarikens IIAC ¹ "the HauptanGprr ^ h are given in the Uhteransprüc ^v s.

In the Praris Irann di "update öes Siolspeic ^ ers in cav way carv ^ e ^ s that the operator", the onset unruM-gen walking the track window over the goal o ^ ne to interrupt the track process manually intervene and Auffrisc ^ ungsimpuls give Irani :. Since the "but orrelationobrackor yourself By J ^v Ho ^v e control of the Maxi Muris of Korrel: ·.-tion function, a statement about the j-üte the ÜboreinstiiBmung between nomen taner / jielstruktur and make -the stored destination can, it is nac ^ the invention possibl ^v defining zn situationsab ^ üngige ÜbereinstimniungsgrenEe a s ^ and enen- and automatically enter a Auffrisc ^ at ^ j ^ rer ünfcersc reitung ungsimpuls.

Another type of automatic learning method is continuous learning, in which only a certain (variable) percentage of the brightness values of the target is recorded in the target memory from a new television picture and an equal percentage is removed from it. Finally, it is also >> conceivable to use a certain percentage at fixed times, e.g. B. 100% of the latest I ¹ V image in the target memory. In the course of a longer ürackvorganges, z. As with frequent target concealment or Einfangfehlern, it happens that the previously centrally intended target nic ^ t ^v r me in. The middle of the memory window ste ^ t, the tracker so something else would follow as the operator. In such cases, previously in tracking systems with contrast trackers, an analog correction variable was fed to the stabilization control loop with the aid of an "offset" via the control handle, so that the tracker, for example, due to its mode of operation, the top of the mast of a ship

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tracked safely, but the line of sight points to a more vulnerable part of the ScM.ffes. This mode of operation, sometimes referred to as ". Knitted", includes its own drifters and is e.g. 3. With land targets, where the center of the target and the desired line of sight are usually the same to the right, it makes little sense. Instead, it is conceivable during the Track process a ^ trukturtracker By J * ¹ Door and Memorybereic ^ sversc ^ iebung force within the riuc ^ bereic ^ it to store other target games and get back on the object's center or! Litte of By J ^v 'Teilverdecloing remaining To ge ^ en keststructure. This operating mode is called "messages".

^ the above suggestion are correlation trackers known, the one just seen at the touch of a button by the operator Z-ielansic ^ t save and z. B. in the following television picture a correlation r.wisc ^ en this stored target structure and calculate the currently visible and determine the storage of the target from this. Is the contrast of the sensor image very little, a view of the target is saved, which is just as noisy as the original image, or the one that is richer in contrast Contains information from the target> background. This leads to a sharp drop in the height of the correlation maximum and thus to unstable track aging pursuing goals but are generally known, for example if an approaching fighter is a dark point on a gray background, it is possible to use the Target memory (PHOM) with such a smooth expectation image and to correlate this with the current target view.

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Since the size of the expected Mld must be adapted to the actual target, it is now necessary to store various target values in PKUMs. The user could, in the simplest>'all by hand a suitable Zielformai; in the same way as he would have to select the target type (tank, aircraft, ship, etc.), but it is easier and more time-saving to provide for an automatic selection of the maintenance targets. For this they offer several solutions:

1. Yes , measurement results from distance measuring devices can be used for direct selection of the PRuH (L&H, iiadar etc.).

2. u s, the cracker itself wii ^v rend the ouc ^ -? Select and ij'infangvorganges the one ~ Ruen that aufvreist the closest match to the aktvellen target. So here the tinhe of the maximum of the correlation function serves as a selection criterion of the PkOM.

3 · During the track process, e.g. B. when approaching the target, the tracker selects the PROM with the next largest target structure when falling below a certain correspondence wave. If the approach has progressed so far that this special target view does not exist, the iracker switches to operation, i. E. > -. Saving the current Z-ielansic ^ t to.

M-. When the target was reached, normal operation would initially be carried out and the point target stored in the PHOPI would only be passed on if the match threshold or a contrast threshold was not reached.

The case is far more difficult with tanks. Here can from no constant structure can be assumed because turret and weapon positions are variable. The ürwaitungsbild could for example from two dark ones of different sizes lying one on top of the other

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S ^ chtscken stand before ^v eilem background. As a mathematical advantage blie ¹ "" the i'Jl imitation dec 311T textured background from the stored Zielansic ^v t.

i)? u: Iτ * oLern öer target concealment kar_n using a precision calculator only "mastered v / ground if the tracker itself" is able to distinguish whether an actual target concealment is present or f ? r it you ¹ - just to change your view clur? ^v VerdreMing is acting. Jt first case passes the tracker temporarily responsibility to Prädiktionsrec ^ ncr, in the second? All v.drd learning the new Zielansic ^v t stimulated.

here '.-: is thought of image processing methods in which z. B. examines ^v t νπ-rd, whether Ir parts of the target image the maximum of the T: ojlt ^? atioi: srn.: il: i-ion etevk sinks, while in other parts of the picture the ^ lol structure is noc ¹ ^ good. In further configurations! It is checked whether an obscuration with the inverse actual 3e3c ^v v / indigküit of the obac ^v processing device runs over the target, which corresponds to standing objects, such as the background In the case of continuous learning, the control of the level of the maximum of the correlation function, which triggers the prediction and switches the learning off if the value falls below a specified Uc ^ wave or one calculated from system parameters.

The automatic return from the prediction to the learning mode sc ^ ie ^ t again through the control of this now threshold calculated according to other points of view, if that Maximum of the correlation function exceeds this threshold.

The previously known possibilities are shown in FIGS. 1 and 2 an Ilensc ^ -I'iasc ^ ine cooperation shown schematically.

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According to FIG. 1, the signal from the image sensor is sent directly to the monitor 2, and is observed by the operator. FIG already showing an image processing insofar as s from the signal line zxvisc ^ image sensor 1 and the monitor 2, a signal transmission to a Zdelve ^ folgungseinric ^ tung 3 ₅ Tracker or ä ^v nlic ^ s, takes place, is acted upon by the servo means.

A further step according to the invention, as FIG. 3 shows, is to switch on the image processing between onsor 1 and the monitor. In this case, all Systemlromponenten correspond to each other and to the operator via the displayed image into üwisc ^v enbilder and symbols from the image processing. Section ¹ - is shown in Fig. 4 · the rack device 3 from Figure 3 in its essential components. "The central 3etrieb3artensteuerung is influenced by the operation panel on the monitor 2 and the servo 4 and controls the track operation. In essence, the analog ΰ sensor signal is converted in the ADC 6 to a digital signal and the actual image processing 7 respectively. The output signal is in a DAC 3 converted into an analog signal and fed to a mixer amplifier 9. Signals from a window generator 10, a character generator 11 and a digital test image generator 12 are also fed into this mixer. The processed sensor image arrives from the Misc >> amplifier 9 in the monitor 2 of the control unit.

The stored or by the tracker By J ^ image processing converted image of the target area can be at a position outside of the image center point, NAC ^{1 "1} required reverse conversion (digital / analog), are shown again. This process offers the possibility of self-control,

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c *> der -ierti.?::.-r ir correct .: ¹ :. TToT.erit on target tracking gesci-al- ¹ Jet · ^ν ~ + ··, ά. ^v . whether he the FLitee aea Zi-Ie? or ne " ^H r followed the background. Werner ZQ ± rt oic ^v inside ¹ -alb the" memory window ", whether all mat ¹ " en- ^% tiPC ^ en operations that v / ä ⁿ -rond c \ er Image processing has been carried out beforehand, is free of errors, or whether too much information is lost. yc ^v letlic ^v is in the memory window ersic ^v tlic ^v whether and -..- how often a switched-on learning process is carried out v; οίο ¹ - ¹ the tracker does not learn from the Ijiel ^v erunter to the background.

i? igur 5 shows a possible arrangement of the riemory window in the .Fer ^ oa ^ picture. In it is V ^ da ™ from JedJ.ener over the target su sliding traclr window and Λ'ι ^{the Tieiaoryfenoter with the 1} "3ii Ziolbil" located in the '.'. IalsOeic ^ sr! or its durc ^ BiIdvGrarl · aitur.g ungev / andolto structure.

In the case of special embodiments of the invention, the following can occur Problems come:

Between an analog written directly on the monitor Image and its counterpart that runs through image processing there is necessarily a time lag of a few pixels. A pixel that is centrally targeted in the analog image appears shifted in the memory window. One can now find a remedy create by the analog image before the representation bycV » running analog delay lines to produce congruent images. However, this always results in a loss of image quality "tied together.

Hac * ¹ of Jirfindung can bypass this problem if the observer is only supplied the digital or any image processing image on the monitor. This representation also serves a good testability a) the entire image processing and

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b) by using ζ. B. digital test image generators of the "f-racker or the image processing device.

For test purposes (documentation) or to warn the operator Before unexpected reactions of the system, it is often of great use to write further information in the sensor image. For example, if the target tracking system is manually guided to a target, the window border could be punched black werdon, "oei safer automatic target tracking but automatically switched to white. Each flicker can be used as an operating system specific Warning should be meant.

Figure 6 shows a block diagram of all discussed Mö code like a target memory 16 in a normal target tracking device 1>, which is shown to the left of the dashed line, can be updated «

The device 15 is for example in the Ui'-PA? 25 04 536-7 has been proposed. For this purpose, the current image of the sluice located in the status quo register is fed to the correlator 18 with a target view in the target register 16, the maximum of the correlation function is determined in block 19 and then for broader image processing and tracking in the block 20 x ^ given.

According to the original invention, the memory 16 is connected via lines 21 one. Memory 22 for older target views (HAM) sojie with a memory 2J for fixed target viewers (PROM) connected, A control logic 24 ensures that they work together in a meaningful way of the status quo register 17 and the target memory 16, while a lerulogic 25 which brings about the decision as to which target view correlated with the register 17 and in what chronological order and what percentage of the target memory 16 is

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should (learn) freshly verden. ? "(Ji e comple eidungskriterien ^v deliver the censors ^r f · ZZ to Tn larger i ^ euerleitanlagen Steven the Lernlogil: 2 ^ öysteminformationen further from the Lasprentfernungsnesser (Lä'I ^v i) and radar JO available at the further ^ Bedi. ^ r ^ r y \ always the riöslic ⁿ -] riding, by J ^ manual üingriff wrong learning processes to interrupt or eeisneten in ^ moments meaningful Lernvorgänce manually trigger also may interfere by J ¹ ^ direct 'intervention on the line J.;. 2 of Suc ^ bereic ^ are in the correlator 18 increases in the television picture Finally, it is conceivable and often of practical use, the operator vrexm nac. ¹ - ¹ own experience a prediction by hand triggers and then xd_eder normal 'frack process, release when the Target can be safely recognized by the tracker.

LICMTIA Patent-Verwaltungs-G .m.b.H.

030015/0 331 BAD OfciÜINAL

Claims (1)

HH 78/03 Sept. 27, 1978 8a / mar Claims 1) · means for detection and tracking of a target, consisting of a optronisc ^ en Mldsensor, a Bildauswertelogik, a Nae ^ guiding function for the image sensor and an operator device, wherein xvelc ^ he the Bildausxirertelogik NAC ^v the PCorrelationsprinzip by comparing the zwiscT-iengespeic ^ erten images of the current scene works with a stored reference profile of the target and, after each image, delivers a storage signal to the automatic control system, characterized in that an electronic decision or learning logic is based on information about the similarity of the different stored and current ones Zielansic ^ t, Zielgesc ¹ · ¹ wind speed, target concealment, etc. for the updating or selection of various target memories connected to a common data bus and that devices are provided that enable information that is important for the operator to be displayed in the monitoring monitor of the control unit . 2) Device according to claim 1, characterized in that the digitally saved target view with the current one Target view is automatically overwritten when the 'match between the two target views falls below a predetermined threshold value or a threshold value calculated from the system parameters. 03 0015/03 31 ORIGINAL INSPECTED HH 78/05 τ 5) iinrichtrung riac ^v claim 1, characterized in that instead of learning after Uhtersc ^ ritung a certain i.:<_>v;3liwert new target views are stored at fixed time intervals and / or continuously at certain percentages in the stored view of the Target recorded. -'-) Device according to claim J, characterized in that in the case of overlaps or a prediction calculator contradicting l'racker results the learning process is suppressed or reversed is made. 5) device nac ^v claims 1 to 3, characterized in that several of them are connected to a common memory bus system. lying "ialoV'eic ^ er (^ AM) are filled with different old target views, to which the correlation computer has access and which are refreshed according to different learning criteria. 6) Device according to claim 1, characterized in that dai3 automatically a selection of previously permanently entered destination views (PHÜIl) made and with these the correlation calculation carried out - ¹ O 7) i.'Jinx'-ic ^ tung nac ^ claim 1, characterized in that the automatic update of the saved target view is always suppressed, xirenn in the correlation tracker The image processing carried out has recognized a partial or total obscuration of the target or other processes. C) Direction to >> Claim 7 ^ characterized in that v / ä ^ rend of a total obscuration of the target after a certain time automatically a larger area for retrieval - 5 015/0331 HH 78/03 - ⁷ J- the target approach selected On " ¹ : ic.c ^v Finding a target approach is switched back to the earlier SucT" strategy. 9) rubbed tuiig nac ^'h to claim 1, characterized in that a PrMdikti-nsrec ^ mer is provided the wrong basis of previous results keikfrrlaten of the target tracker prevented and possibly on older target views before a dherging surüc'-tgrpift. 10) jiinric ^ bung NAC ^v claim 1, characterized gekeruizeic ^ net that each NAC ¹ "vcd ueen Prädiktionnrec ^ ner detected accelerations of the target relative to the aiming line and during the first Ji'infanFcvorganges the target area with variable üuc bereic ^" ^ off 11) means IIAC ^ claim 1, characterized in that the stored, optionally By J ^v image processing umgevjandelte Zielaiisic ^v t in a small part of the monitor BiIdes e ing el) is et end. 1 12) Device according to claim 1, characterized in that the window edge of the stamped memory window and / or the track window on the display of certain operating modes in its color or brightness is switched. 13) Device according to claim 11, characterized in that the entire sensor image processed by the tracker or image processing device z. B. for test purposes (built in test equipment) only after the conversion has taken place through image processing is shown on the monitor or the observation device. 03 0015/0331 BATHROOM ORIGINAL Hi ₁ 73/03 - 4 - 14-) rub-in according to claim 1, characterized in that to awaken documentation and to support the operator current oyotem information through certain symbols, letters, Measurements or words in the picture of the observation device be displayed. 030015/0331