FR2570195A1 - OPTOELECTRONIC TARGET SEARCH APPARATUS FOR ENTRY AND AUTOMATIC DETERMINATION OF THE GOAL ON BOARD CARRIER VEHICLES - Google Patents

Abstract

A. OPTOELECTRONIC TARGET RESEARCH DEVICE ALLOWING AUTOMATIC SEIZURE AND DETERMINATION OF THE OBJECT ON BOARD VEHICLES. B. APPARATUS CHARACTERIZED IN THAT THE DETECTOR IMAGE DATA IS TRANSFERRED TO GENERATE DUALIZED IMAGE DATA BEYOND AN ADJUSTABLE AMPLITUDE THRESHOLD, THEN ARE APPLIED TO CORRELATORS FOR PROCESSING USING OBJECTIVE MODELS, LIKELY TO BE SELECTED, SHAPED BY STATISTICAL IMAGE DATA. C. THE INVENTION RELATES TO AN OPTOELECTRONIC TARGET RESEARCH APPARATUS.

Description

"Target search device, opto-electronic allowing a seizure

and automatic determination

  of the objective in carrier vehicles. "

The present invention relates to a

  opto-electronic target capture device for

  Automatically search for, capture and measure targets using an image detector on a platform

  tilting stabilization system and an installation of

  order and the exploitation of images thus ordered and in which data correlations are processed.

  image detection and statistical image data.

stored in memory.

  When monitoring intervention areas and detecting constitutive objectives

  targets, it is known to monitor spaces cor-

  responders for example using flying machines-and detecting them with image sensors. The image data that can be obtained by such an implementation

  may be transmitted, for example, to a

  director on the ground and be transferred from there to monitors

  for a corresponding treatment. The observation of

  allows a person in charge of control, exploitation and

  the image data of the intervention spaces, entered and to carry out objective determinations as described for example in the document DE-OS

25 19 241.

  The means described above for the capture of a target and the determination of an objective, however, are insufficient and this because the use of a person providing control in the director's post,

  constitutes a factor of insecurity. In addition, such a system

  monitoring system and the automatic capture of targets at a great distance, for example beyond the limits within sight

  Important angular ranges are not suitable.

  The invention thus aims to create an opto-electronic target search device, of the above type, allowing automatic capture of the target and automatic determination of the objective on board carrier vehicles. In addition, the invention aims to ensure the capture of targets and the determination of objectives, automatic, long distance and in

important angular ranges.

  For this purpose, the invention relates to an apparatus of the above type, characterized in that the

  detector image data are transferred for gen-

  rer dualised image data beyond a threshold

  adjustable amplitude, then applied to correlations

  processors using selectable lens models, formed by data

statistical images.

  According to another characteristic of the invention, the adjustable amplitude threshold is determined in a comparator as a function of the predictable target classes by combination of the statistical parameters.

  of each image (exploitation of the histogram).

  According to another characteristic of

  the invention uses rotational invariance models

  of targets for the lens models and which are adapted in size from the upper edge to the lower edge of the image by the detector alignment device

  directed inclined forward.

  According to another characteristic of the invention, the apparatus for example onboard a combat aircraft receives system data such as the flight altitude, the resolution of the detector and the direction of sight of the detector and the type objectives and reference models calculated from

there for the lens models.

  According to another characteristic of the invention, the correlation between the dualised image data is done with the data of the objective models

invariant in rotation of targets.

  According to another characteristic of

  the invention, the objective abstract models are decomposed

  three partial models whose data are

  are linked by correlation in one of the three corre-

  parallel reflectors to dualised image data.

  According to another characteristic of

  the invention, the image detector is an imaging detector.

  passive for example an infra-red camera or a

microwave radiometer.

  According to another characteristic of

  the invention, the image detector is an imaging detector.

  active management such as a radar detector.

  According to another characteristic of

  the invention, the tilting of the stability platform

  sation is done with a triangular movement.

  According to another characteristic of

  the invention, the tilting of the stability platform

  sation is done with sinusoidal motion.

  According to another characteristic of

  the invention, the tilting of the stability platform

  sation is done with a sawtooth movement.

  According to another characteristic of

  the invention the tilting of the stability platform

  This is done in a spiral motion.

  According to another characteristic of the invention, the iPlate-stabilization form is associated

  to a laser telemetry device.

  According to another characteristic of

  the invention, the low level of the stability platform

  is done after a successful goal search on

  the objective detected using the stability platform

  tion. According to another characteristic of the invention, the data of the original images received are applied to an image enhancement unit which, by a histogram exploitation, generates a line of

  transfer (polygonal path) has an adaptable image content

  tif and ensures optimal image representation.

  Finally, according to another characteristic

  that of the invention, the relative position of a detected objective is made visible at the console of the

pilot by spot projection.

  The optoelectronic research apparatus

  The number of targets may comprise a passive image detector, for example an infra-red image detector.

  or a microwave radiometer. It is also possible

  to use for this purpose an active detector such as

  example a radar detector. The stability platform

  thus offers the possibility of sweeping in the area

  a large angular range

  platform. For rocking movements

  Depending on the requirements, movements can be

  triangular, sinus, sawtooth or spiral

  the speed of the tilting movement is a function of the aiming direction and the speed of the carrier plane, for example a fighter aircraft, so as to obtain sufficient overlap of the images in the tilting period, ensuring a high probability of capture and distribution of objectives. Furthermore,

  when using an image sensor to be infra-

  red, it is advantageous to convert this detector to continuous detection or detection of semi-images instead

  to have the usual CCIR standard. Images or ex-

  image lines of the intervention space, monitored using such detectors are operated as will be

  described below for the capture of the target and the determination

nation of the goal.

  The present invention will be described in more detail with the aid of the accompanying drawings, in which: - Figure 1 is a block diagram of

  the entire opto-electronic aiming device.

  FIG. 2 is a block diagram of the switching stages for the automatic capture of an objective. - Figure 3a shows the structure of

  reference of an abstract grid of an objective.

  - Figure 3b shows the distribution

  in a reference grid of a research model.

  The optoelectronic aiming device shown in FIG. 1 consists of an infra-red image camera 10 which is provided on a tilting stabilizing platform 11. This platform 11 also carries a device telemetry laser 12 which, like

  the infra-red camera 10, cooperates in both directions.

  data. 13. This makes it possible to determine

  move away from a target and adjust the field of view of the camera. The output data of the infra-red camera 10 is first transmitted to an analog-to-digital converter 14 which provides digital image data to the switching stages 15 for automatic lens acquisition and to a single stage. of

  switching 16 for image enhancement. The conversion

  digital-to-digital weaver 14 and the switching stage

  16 for image enhancement are ordered equally

  The data bus 13 cooperates in both directions with a central computer 17 and a memory 18. In addition, a clock generator (clock) 19 provides its data signals.

  rate to the data bus 13 and the data of the aircraft-

  carrier for example a fighter aircraft such as the speed of the aircraft, the height of the aircraft etc which are introduced into the data bus by a block represented

schematically.

  Digital image data from

  the switching stage 16 to improve the image arriving

  wind in a digital-to-analog converter 21 via the data bus 13; the converter

  transmits the converted image data back into step

  by an image mixer 22 to a visual display device.

  23 input keys. This visualization device

  In addition, FIG. 23 further cooperates with a field of view inverter 24 via a data bus 13 so that targets determined by a simple key input can be represented on an enlarged scale. A symbol generator 25 associated with the image mixer 22 and controlled by the data of the data bus 13 makes it possible to insert certain symbols into the image data and to make them appear on the display device 23. These symbols images can be reproduced on a

  spotlight 26 which identifies the direction of the position

  the lens at the pilot console.

  A second display apparatus 27 which is controlled, for example, to form the reticle, by means of a symbol generator 28 with a computer cooperating reciprocally via the data bus 13, thus makes it possible to align the longitudinal axis

of the plane on the chosen objective.

  Figure 2 shows the scales .- .. d.

  details of the switching stages 15 for the automatic input

  of an objective in the whole of the apparatus of

  opto-electronic focus. These switching stages refer to

  in more detail in the block diagram and connected to each other, the aim is in practice to automatically search for the veracity of particular objectives.

  images taken by the infra-red camera 10, deter-

  undermine their position-image and stop the tilting of the stabilization platform ll when the search for the objective has succeeded. In addition, the infra-red image camera 10 must be aligned to

  visual identification of the objective with the help of

  image loss by the switching circuit of the field of view. The basis of automatic lens recognition is a correlation of image data

  received and dualised with an abstract model of the lens.

  This dualisation of each image of the infra-red image camera 10 is done in the comparator with an amplitude threshold which is determined as a function of the foreseeable objective class by the appropriate combination of

  static image parameters (exploitation of a histo-

  gram) determined individually for each image.

  To avoid too much error resolution, for example

  ple for unfavorable statistics of the image received,

we give up a farm.

  To have a fast and simple correlation, one uses in addition to the dualisation of images (1 bit of resolution of the scale of the gray) models

  of invariant objectives in rotation of the objective which,

  that the image camera 10 is aligned in an inclined manner, are adapted from the top to the lower edge of the image, in the sense of the quantities. By transferring the data from the aircraft carrier system and the camera as indicated by block 20 in FIG. 1, the reference models can be calculated using the altitude, the resolution of detector and sighting direction as well

  than the type of objective to be determined. Models of objec-

  In this case, the rotational invariants are distinguished by a 100% coincidence within the smallest dimension of the objective and a certain correspondence.

  for example to 66% for the largest dimension of the ob-

  jective. A correct determination of the objective required

  Furthermore, a 0% coincidence in the outer zone

  re (separation of the background).

  - Figure 3a is a typical structure

  characteristic of an abstract lens model for aligning

  vertical and inclined sensor; the dimensions of the different parts of the model must be chosen in

  according to the dimensions of the objective as well as the

  flight meters and sensor settings. Letters

  L and H designate in the present description the terms

  "low", that is, down and "high" that is,

  say up. To establish simply and quickly

  correlation, we break down this abstract model of

  three partial models which are linked by correlation

  independently from each other in one of the three correlators. Figure 3 shows the subdivision

  chosen with the three correlation models that result

  tent and different mask patterns that, in conjunction

  with the altitude information of the objective as informa-

  memory depth were recorded in the target reference memory. The width of the model

  correlation behaves proportionally to the

  of the xmax objective and can occupy

  taken between 10 and 64 pixels. Image points not used here should be covered by the information

of mask.

  To carry out the correlation, correlators corresponding to models 1 to 3 are introduced into the shift registers in parallel, the infra-red image data dualised and

  memory intermediately, line by line. Lors-

  that the correlators of models 2 and 3 exceed a predetermined degree of correlation, the column addresses of this image point are recorded. We can record

  in this way, 16 addresses in the address memory

  his. When going to the next line, when the predetermined degree of correlation is reached, the addresses are retrieved and compared to the addresses

  stored in memory. If the difference between the two

  its is not greater than +/- 1 point-image (inclined arrangement of the objective in the image) then one saves the compared address and a number n. This number n expresses the

  number of lines compared. For a more important difference

  carrying, the first address is recorded first. The result of the correlator for the model 2 is further entered in an addition memory of a comparator-adder. This comparator-adder also controls whether at this moment for example 70% of all the image points of this frame are of "high" level and the operation then stops. The operation of the addition memory is then carried out in a tolerance line M that arises when the number n

  reaches the predetermined and predictable number of lines M.

  In addition, an address window is calculated in this tolerance line M and this address window is checked for the next line using the correlator.

  for model 1 if the "low level" condition is satisfied

  made. When in this case there is also a predetermined degree of correlation, the objective is defined.

  as recognized. From this point of view, we can record

  intermediate register the addresses of the columns

  and lines and introduce them into a memory of sym-

  bols by an address transformation circuit which

  calculate the average address of the objective.

  The diagram of FIG. 2 which, as already indicated, is an overview of the structure and operation of the switching stages for the automatic capture of an objective comprises some of the switching stages realized three times in parallel and can perform an image exploitation practically following a real-time processing at a rate of 40 ms. the

  where the duration of use of an image may correspond to

  at 120 ms, it is possible to give up treatment

in parallel.

  The coordinates of the calculated objective

  in the manner described above for a purpose-

  target, grabbed, serve to align the image camera to

  infra-red 10 (the closest coordinates

  at the instantaneous position of the stabi-

  to identify the target. As soon as targets are detected in an image, this image can be represented on the display apparatus 23 including the inserted marks, and acoustic signaling attracts the attention of the control personnel. Because the optical detection axis is aligned with the nearest lens, visual recognition of the target is by a single field of view switching circuit. In this

  In this case, it is possible to identify the target using the

symbolizer 25.

  To display the position of the target relative to the position of the carrier, one can

  insert in the image represented, an angular measurement

  re, the location of the target using a spotlight, at the appropriate place on the console of the

  pilot. For target targets detected from this

  nier, there are other on-board computers on board

  in a fighter plane for further treatment.

  The laser telemetry apparatus 12 thus serves for exact calculations of the dimensions of the reference image or the positions of the objective. (The CCIR standard is given by the International Advisory Committee of

  radiocommunication) (625 lines / TV).

Claims (11)

CLAIMS S   1) Opto-target capture device   to automatically search, seize and measure   targets using an image detector on a tilting stabilization platform and an image representation and   commanded and in which the correlations are processed   images and data detection data   of statistical images, stored in memory,   in that the sensor image data is trans-   generated to generate dualised image data beyond an adjustable amplitude threshold, and then applied to correlators for processing using selectable lens models formed by statistical image data.   2) Target capture device, opto-   electronic device according to claim 1, characterized in that the adjustable amplitude threshold is determined in a   comparator as a function of the predictable target classes   by combining the statistical parameters of each   image (exploitation of the histogram).   3) Optoelectronic capture device   as targets according to any of the claims   1 and 2, characterized in that   invariant rotation of targets for objective models   tif and which are adapted in size from the upper edge to the lower edge of the image, by the alignment device   of detector directed inclined forward.   4) Optoelectronic capture device   as targets according to any of the claims   1 to 3, characterized in that the apparatus for example em-   on board a combat aircraft receives system data such as flight altitude, detector resolution, and detector   type of objective to be grasped and standard reference models   abut from there for the lens models.  ) Optoelectronic device of   Target capture according to any one of the claims   1 to 4, characterized in that the correlation between the dualised image data is with the data of the target invariant target rotation models.   6) Optoelectronic capture device   target set according to any of the claims   1 to 5, characterized in that the abstract models of objec-   tif are decomposed into three partial models whose respective data are correlated in one of the three correlators parallel to the dualised image data.   7) Optoelectronic capture device   target set according to any of the claims   1 to 6, characterized in that the image sensor is a   passive image detector, for example a camera with infra-   red (10) or a microwave radiometer. 8) Optoelectronic device of   Target capture according to any one of the claims   1 to 6, characterized in that the image sensor is a   active image detector such as a radar detector.   9) Optoelectronic capture device   target set according to any of the claims   1 to 8, characterized in that the tilting of the platform   stabilizing form (11) is made with a triangular movement. ) Optoelectronic device of   Target capture according to any one of the claims   1 to 8, characterized in that the tilting of the platform   stabilization form (11) is made with a sinusoidal movement. 11) Optoelectronic device of   Target capture according to any one of the claims   1 to 8, characterized in that the tilting of the platform   form of stabilization (11) is made with a movement in Sawtooth. 12) Optoelectronic device of   Target capture according to any one of the claims   1 to 8, characterized in that the tilting of the stabilizing platform (11) is in a motion spiral. 13) Optoelectronic device of   Target capture according to any one of the claims   1 to 12, characterized in that the stabilization platform   tion (11) is associated with a laser telemetry apparatus (12). ) Optoelectronic device of   Target capture according to any one of the claims   I to 13, characterized in that the tilting of the platform   stabilization form (11) is made after a successful lens search (10) on the target detected using   of the stabilization platform (11).  ) Optoelectronic device of   Target capture according to any one of the claims   1 to 14, characterized in that the data of the original images   received is applied to an image enhancement unit (16) which, by histogram operation, generates a transfer line (polygonal path) to an adaptive image content and ensures optimum quality image representation. 16) Optoelectronic device of   Target capture according to any one of the claims   1 to 15, characterized in that the relative position of a   detected objective is made visible at the level of the   pilot's sole by spot projection.