FR2480424A1 - AUTOMATIC AIR-AIR OR AIR-FLOATING DRIVING SYSTEM - Google Patents

Abstract

THE INVENTION RELATES TO AN AUTOMATIC FIRE CONTROL APPARATUS FOR WEAPONS MOUNTED ON AERODYNE. IT INCLUDES AN ADJUSTABLE TELEVISION CAMERA COUPLED TO ONE OR GYROSCOPES, AND AN AUTOMATIC TELEVISION TRACKING SYSTEM USING A PROCESSOR TO KEEP THE CAMERA CENTERED ON A TARGET PERMANENTLY, AND TO CONTROL THE ORIENTATION OF THE MOUNTED WEAPON ON THE TARGET. AERODYNE AS A FUNCTION OF THE DIRECTION OF THE AXIS OF THE CAMERA, DIRECTION INDICATED BY DETECTORS ASSOCIATED WITH GYROSCOPES. THE TARGET ACQUIRED IS DONE ON A TELEVISION SCREEN ON WHICH AN IMAGE OF AN AUTOMATIC TRACKING SYSTEM HANGING WINDOW IS SYMBOLIZED. THE PILOT'S FUNCTIONS ARE THUS SIMPLIFIED AND THE INFLUENCE OF AERODYNE INSTABILITY IS ELIMINATED.

Description

The present invention relates to an automatic fire control system

  for weapons mounted on aerodynes, and in particular for

mounted on helicopters.

  That the crew of the helicopter or aerodynne comes down to one man who is both pilot

  and serving as a firearm, or

  you and a co-pilot or a separate gunman, you always face the problem of the difficulty of

  precisely caused by the instability of the aerody-

  ne: aiming and keeping the target in the axis

  shots are very difficult, especially for a helicopter

  even if the pilot is excellent or if the aircraft is

  dyne is in autopilot mode, because of

  the instability of the aircraft's attitude and vibratory

  tions of it: even with the most advanced

  autopilot helicopters, a residual oscilla-

  as well as vibrations. In addition,

  the copter must be used in air-to-air or air-to-ground combat almost always very close to the ground, and the pilot, whether on autopilot or not, must also

  steer and steer his camera continuously

  movement of the target he seeks to reach.

  dre, which makes it difficult to aim at stil is himself the shooter, or that of the separate weapon servant

if it exists.

  It therefore seemed desirable to design an automatic fire control system that takes into

  instead of the shooter a number of

  that he was required to complete each shot,

  and above all, that make the shot independent of the instabilities

  control units and the helicopter vibratioii.

  The present invention proposes for this purpose a means cbmm on which serves to enslave the pointing of a weapon poated by the helicopter to the aiming direction of a target acquired by the shooter, the shooter n ' having to acquire the target only once, and the system then stalling on this target to automatically follow it and to follow accordingly to the weapon, until the triggering of the shot, a direction Clean to allow a impact on the target, that is to say, a direction pointed exactly on the target

  an out-dated management taking into account

  trajectory of the projectile thrown at the weapon.

  The automatic fire control device of the invention includes at least: a television camera with its optical system

  mechanical and optical means of

  its optical axis in relation to the aerodyne; means for controlling said orientation means, comprising at least one stabilization gyro and

  means for applying one or two pairs of pre-

  transfer to each gyroscope, the gyroscope being provided with orientation detectors providing control signals to the orientation means of the optical axis of the camera; an automatic television tracking system using a signal processor to generate, in

  synchronized television signals with those of the

  mera, an acquisition window located in the field of view of the camera, and to move the window in this field, either under the action of a control means, or in response to variations of the image signals

  detected by the camera, within the window of

  rocking, to maintain the window centered on a given image sector, by displacements of the optical axis of the camera;

  - a display means on a TV screen of the

  acquisition with its variable position, super-

  posed or not to a TV picture of the landscape detected in the field of vision of the camera; Such a TV screen will be introduced either into a so-called head-up viewfinder, or into a helmet viewfinder, by optical means known per se, so that the image of the acquisition window is perceptible to the shooter on the landscape real that he observes, projected

  to infinity. The visualization of the TV image

  the actual image of the landscape will not be used

  with the aim of harmonizing the directions of the mechanical and / or optical reference axes of the television camera on the one hand, of the head-up viewfinder

  or the helmet visor on the other hand.

  control means for modifying the position of the acquisition window in the field of view of

  the camera and on the TV screen in order to bring it

  the target to be acquired, and switching means

  to put the tracking system into action

  tomatic that will automatically maintain the window centered on that target. This control means can be manual. It can also be a helmet viewfinder whose optical axis is linked to the direction of gaze

  of the shooter. These two means can be mounted simultaneously

  element and used separately by switching, - means of orientation of a weapon mounted on the aircraft;

  a processor able to use the characteristic signals

  the direction of!, opaque axis of the camera and the

  signals characterizing the direction of the window of

  quisition and the target in the field of vision of the camera and possibly signals representing other parameters influencing the firing direction, to generate two groups of control signals: those of orientation of the optical axis of the camera, and those intended for the orientation of the weapon.

  In target acquisition mode, it is the orga-

  manual control which is operated to bring the acquisition window around a target; in the mode of

  continuation, the optical axis of the camera is moved angu-

  in such a way that the window brought to the target remains centered automatically on that target even if the target moves as a result of its own

  movements or those of the aerodyne shooter.

  The processor also directs the weapon,

  the direction of the acquisition window, thus the direction of the optical axis of the camera, which is known using the aforementioned angular sensors, and introduces weapon pointing corrections according to other parameters such as, without limitation, the

  speed, the distance from the target, the nature of the

  nition and its temperature, the aerological data

concerning shooting space, etc ...

  The speed of the target will be measured by the TV tracking signals as they are applied to the control means of the orientation means of the optical axis of the camera. The use of linear precession control gyroscopes makes it possible in particular to use to obtain a parameter representative of said speed, the measurement of the control currents of the (doe) gyroscope (s), current smoothed by

  the response inertia of the gyroscope (s) to these cou-

  rants. The distance measurement is preferably obtained by a laser or radar rangefinder whose optical axis is oriented and stabilized by the same means as those of the camera. In the particular case of the neodymium laser range finder the laser optics and TV camera can be

very widely common.

  The fire control system operates in the following manner: the pilot directs his helicopter towards a target to be attacked, so that this target enters at a given moment in the field of vision of the

  television camera. This field can be advantageous-

  the pilot or the shooter can check that the target has entered the field of the camera either with the head-up viewfinder or the helmet viewfinder above the target thus discovered, the shooter activates the one of the two aforementioned control means for moving

  the acquisition window, generated in the form of

  television and visualized on the above-mentioned TV screen (s) until this window comes to frame the target. The acquisition of the target is then made and the operator, by acting on a pushbutton switch, switches the fire control system of the "acquisition" mode (where it is an external member that can act on the position from the window) to the "tracking" mode where the tracking system is responsible for acting through the processor to move the optical axis of the TV camera so that the window

  be maintained centered on the target that was acquired.

  In "tracking" mode the system processor

  pursuit receives the television signals from the

  mera therefore the image signals of the targets he knows since he generates them the TV signals that correspond

  at the acquisition window and therefore knows its

  data X and Y. I1 compares according to two rectangular axes

  variations in the amplitude of the television signal (luminance variations) of the points characterizing the

  target within the acquisition window in use

  directly reading contrast amplitudes or using

  the forms they represent (correlation of images) and determines the control

  orientation of the optical axis of the camera to

  to keep it focused on the target despite

  relating to the aerodyne and the target.

  It requires other than the orientation of the weapon carried by the aircraft, copy at any time the direction of the optical axis of the camera so that the operator has to trigger the shot without worry about the direction of the weapon. This may be permanently pointed at the target or remote from a quantity function of parameters already mentioned such as the relative speeds of the aerodyne and the target or the shape s. tial and temporal trajectory of

projectile launched.

  To perform this automatic orientation of the weapon, two solutions are theoretically possible, although the first may seem more sare and more practical.

  a) in a first solution, the assertion processor

  already quoted discriminates a tendency of the target therefore the acquisition window to deviate from the optical axis of the camera, and it then gives immediately

  orders to change the orientation of the optimal axis

  camera to restore the position of the axis

  on the target by acting on the means already

  including the stability gyroscope (s)

  tion; the weapon for its part is oriented by at least two servocontrols which receive from the processor control signals taking into account both the position of the optical axis of the camera and the other firing parameters indicated above. The weapon then tracks the direction of the optical axis of the TVo camera in orientation (with firing corrections near) b) in a second solution, the processor makes a devometric measurement of the direction of the target with respect to the axis optical camera, that is to say

  that it identifies in two perpendicular directions de-

  writing the field of view of the camera the coordinates

of the target.

  From this measurement and that of the direction of the optical axis of the camera, as well as that of other parameters (firing corrections), it determines the pointing direction that must be given to the weapon in relation to the optical axis of the camera. At the limit this axis could be invariable (fixed camera), the pilot having to maintain by piloting the aerodyne the target in the field of vision of the camera; but in the general case the camera or its optical sighting system is mobile, controlled by one or two gyroscope (s) which stabilizes the orientation of its axis and make it independent of the movements of the aerodyne; in this case, the processor constantly receives information on the orientation of the optical axis of the

  camera and he combines this information with the

  tometric position of the target as well as

  very parameters to communicate to the means of orientation of the weapon an indication of the direction that the weapon must take. This cystus, by its statism, may be advantageous, but it is metrologically less scrupulous than the one which consists of the following.

  camera on the target and to hold it there by

is lying.

  Moreover, in both cases the weapon is stable

  1isée in direction puiscu'asservie towards a

dispositf gyrosconoiaue.

  We will now specify the various components

  jumps of the fire control system according to the invention. The television camera is an electronic and / or mechanical scanning camera

  operating either in visible light or in

  sible (especially in the far infrared band). It is provided with an optical system

  which can be complex and

  dioptric or catadioptric or mixed magnifying magnets, with fixed or variable focal lengths continuously or

  not to vary the extent of the field of view when

that conditions demand it.

  The vision system can be mounted independently

  of the camera, and, when speaking in the present

  description of an orientation of the camera or its axis

  optical, we must understand that we try to orient the optical axis of the camera and that consequently we can

  to orient either the camera itself or an optical system

  or part of an optical system placed in front of the ob-

  the camera, this system does not necessarily have an optical output axis coincide with the optical axis

of the camera itself.

  In particular, we can in many

  the case of a set of mirrors, prisms and lenses

  to divert light rays received or emitted

  a specific optical axis to direct them to the camera.

ra according to a different optical axis.

  In these conditions, it is perfectly

  possible to provide for the stabilization and orientation

  the camera's aiming axis, three solutions: - the camera and its optical sighting system are carried by a common support mechanically coupled or servocontrolled in orientation by means of engines with one or

  several gyroscopes capable of receiving electrical signals

  angular positioning control rods, by applying precession torques to these gyroscopes

  - the camera is fixed directly on the frame of the

  rodyne and it is the optical system that is coupled mechanically

  nically or slaved to gyroscopes; the optical system is fixed to the frame of the aerodyne and

  it is the camera that is coupled to or controlled by the

gyroscopic drugs.

  In the first case: it is often a platform

  form hinged to the cardan with respect to the frame, and rotatable in several directions by positioning motors, which will be used to carry the elements (camera, rangefinder) to guide and stabilize, the latter receiving for this signals of command of

  angular positioning, especially when

  to orient the optical axis of the camera so

  that he be constantly directed on the target.

  In the second case: the optical system advantageously include one or more mirror (s), and / or one or more mobile diasporameter (s). The

  moving parts, whether it be the camera set and the

  the aiming system, or the aiming system alone, are

  seen from angular sensors which give information

  on the orientation of these elements, therefore the optical axis emerging from the aerodyne frame,

  this information being used as a back-up

  and for the fire calculations previously defined

  is lying. The mentioned processor is in practice a programmable microprocessor to fill a certain

  number of measurement, calculation and management functions

  systems, including, in particular,

  generation in the form of television signals

  symbols such as the window symbol of acquisition

  which must be displayed on a television screen at a variable, adjustable and measurable position, or other symbols of firing aid or piloting: for example a symbol indicating the direction in which

  the weapon is pointed (direction which is generally different

  ferent of the direction represented by the position of the latching window); or one or more symbols

  delimiting the maximum fields of action possible (de-

  maximum beats for viewfinder or firearm) camera field of view; a symbol representing the future iont "of the shot, that is to say the point of theoretical impact which is the spatial convergence point of the projectile and the target; one or more symbols for the piloting of the aircraft such as : available power, position in space, trajectory, one or more system management symbols such as: - on or off - ready shot - alarm (s) - target distance, target speed etc.,

  All these symbols can be fixed or

  cynical, with variable frequency, and colors

  different can be used. We are well aware of

  you can program processors to generate all these symbols and introduce them into a TVo circuit The television screen that displays them can receive

  for harmonization, the television signals of

  TVs directly from the camera, to superimpose the symbols (and especially that of the hanging window) an image of the outdoor landscape seen by the camera and transformed into a television image. For the

  normal service of the system, the shooter is provided with a

  helmet or uses a "head-up" viewfinder, incorporating both on a TV screen, and allows him to directly see the outside landscape, so the target, through a semi-reflective ice that

  overlay the television image of the differences

  symbols generated by the processor and especially

  respecting its effective direction, the window of

  quisition. Headset viewfinders with a built-in or fiber optic TV screen perform this image overlay through a single-lens lens in which the symbols appear projected on the screen.

  infinity superimposed on the landscape.

  The orientation of the helmet visor is measured

  at any time to establish a relationship between the position of the symbols and the position of the television camera, that is to say in practice a coincidence, subject to harmonization as already indicated, between the field of view of the viewfinder helmet and that of the - camera. We know how to measure the orientation of the axis

  optics of the helmet visor lens so the direc-

  the gaze of an observer wearing such a helmet visor. This measure is used in this

  invention, in particular for moving the window of acqui-

  in the field of the camera or to steer the axis

  optical camera towards a target in order to acquire

  sition by simply rotating the operator's head

  Yes. directs his gaze towards the target.

  In the case where a "head" finder is used

  high ", fixed in relation to the aerodyne, its semi-ice

  reflective allows to see the landscape directly

  outside the target, and to project more

  placing on it the synthetic images of the

  nrch and other symbols, and the TV image of the landscape for harmonization purposes. The use of a helmet head that can rotate with the shooter's head is more favorable because the "head-up" viewfinders have a vision and projection of synthetic images

  limited to twenty degrees.

  The television tracking circuits, coupled to or part of the camera and the processor, are currently well developed for tracking a target through a snap window that moves into the camera's field of view. in

  remaining centered on the target that has been designated to him.

  In a process this target is identified by the analysis

  luminances qmentres ui characterize it.

  The average luminances near the point, on either side of it, in two or more

  perpendicular directions are measured as soon as

  sic'tion of the target, and the acquisition window is moved in these two directions to maintain these luminances (or at least their ratios) to their measured values, this despite the movements of the target in the field of view. In reality, the window

  is a succession of temporal electric

  at a rate of one per line on some television scan lines by a generator synchronized with the scanning of the camera, the position of this slot the

  along the scanning line, that is to say, its

  wise compared to the beginning of sweeping, as well as the

  position of lines with a slot, being

  from the outside in target acquisition mode or automatically in tracking mode thanks to the servo loops that move the slot into

  height (line position) and in length, in the center

  always on a region with a given luminance contrast. In another process, the elementary luminance determines the design of the target. This drawing is put in memory then compared to the new drawing, then a correlation calculation delivers the signals of deviation

necessary for the pursuit.

  The function of calculating the orientation of

  the weapon at all times during the pursuit is

  using distance information between the aircraft and the target, and the speed of the target relative to the aircraft, to detach the weapon from the target in such a quantity that the projectile launched

  the weapon reaches the target despite its

  ments. To schematize the principle of the invention,

  there is shown in the figure an exemplary embodiment.

  This example is schematic and drawn in such a way as to

  understand the functions performed by the system of

  fire control; given the complexity of each

  each of the subassemblies used, and because these subsets are known, the invention has not been shown in more detail, and the lines joining the

  blocks of diagrams represent functional links

  them and not real connections between subsets.

  In addition, some elements were voluntarily

  for clarity of function representation, but it should be understood that these subsets

  in practice: for example, the cir-

  television tracking can be part of the processor, the symbol generators to be displayed on the television screen and the snapping window generator can be part of the same set and be tightly coupled to or part of the processor, etc.

  Finally, although we have not spoken so far

  if on the drawing, than two television screens, the one that is integrated into the helmet viewfinder head, it can also provide one or more other TV screens, for example a screen in the cabin of the aircraft, to the

  provision of a second operator, or more.

  It is thus possible to provide one or more means of recording

very magnetic or otherwise.

  We will now indicate examples of implementation of the invention, either with a single shooter,

  the pilot; with a pilot and one or more

very operators or shooters.

  The method of implementation comprises a target acquisition phase and a phase of continuation before triggering the O-phase fuse - Preparing the firing by introducing the data

  Permanent or semi-permanent prerequisites.

  Proceed with the harmonization by displaying the image of a characteristic landmark and act on the harmonization adjustment means to make this landmark coincide with the acquisition window, or

  record in memory the observed discrepancies.

Phase 1 - Acquisition

  the case: use of a head-up viewfinder

before the pilot's head.

  if necessary switch the system of

  shot shooting on a "head up" viewfinder position;

  activate the appropriate control to

  set the optical axis of the camera in the liaerodyne axis; discover a target at sight O fly the aerodyne to bring the target into the head-up field of view (generally the field of acquisition of the camera viewfinder

  is greater than the field of vision of the said

  head high); 10. observe the symbol called "window" displayed in the head-up display (possibly

  also the symbols of service and

  adequate age); move the "window" symbol towards the target by acting on the corresponding control (joystick or two-axis button) while maintaining approximately the alignment of the aerodyne;

* frame the target with the window in process

  if necessary to readjust manually its dimensions according to the reaction of the target and its environment, or leave

  act an automatic readjustment device

  that of said window; order the commissioning of the continuation

automatic television.

  check this commissioning by observing the rallying of the optical axis of the camera, the pursuit, or a light, or a corresponding service symbol, in the viewfinder head

high.

The acquisition is complete.

  2nd case: Tilting of a helmet viewfinder: switch the firing line to "helmet viewfinder", which slaves the orientation of the optical axis of the camera to the optic axis. the operator;

  visually discover a Dar target

  the head; pilot if necessary the aerodyne to keep the target in the field of view of the camera viewfinder; To observe the symbol called "window" in the

  helmet visor (TV screen pro-

  thrown into the eye of the operator); then proceed as before to move the acquisition window to the target, frame it and switch the

  system on the commissioning of the

automatic suite.

The acquisition is complete.

  Phase 2 - Prenaration of Fire and Shooting Observe the appearance of the future point symbol as soon as the fire calculations are completed; to pilot the aerodyne so as to bring if necessary and to maintain the symbol "future point" in the field of fire of the weapon, this field being visualized either in the viewfinder

  head up, either in the helmet visual.

  To press the trigger of the weapon. Shooting begins after automatic verification by the process, that all conditions

  are satisfactorily fulfilled.

  you. In case of emergency, it will be possible to use a crossing switch of this

provisional ban. Next phases - observe the results of the naked eye shooting

  display the TV picture either in the head-up viewfinder, in the helmet viewfinder, or on a TV screen; to begin again ab initio or not the phases of acquisition and preparation tiro D- -j-VVxDjCe TIO '; S i - Apparatus of automatic conduct of shooting for weapons mounted on aerodyne, characterized in that it comprises: 5. a television camera with its optical sighting system and means for orienting the optical axis of this sighting system with respect to the aerodyne;

  control means of these means of orienta-

  comprising a gyroscope (s) and means for applying two pairs of precession

  to, or at each gyroscope, the gyrosco-

  spike being provided with direction detectors providing control signals to the orientation means of the optical axis of the camera;

  an automatic tracking system for televi-

  using a signal processor for

  generating, in television signals synchronized with those of the camera, an acquisition window located in the field of view of the camera: a) to move the window in this field under the action of an external control means, or in

  response to variations in the video signals

  by the camera inside the snap window to keep the window centered

  on a given image sector despite the displacements

  optical axis of the camera.

  (b) to move the optical axis of the camera so that the camera is slaved to the

  direction in which a Target is detected

  ted. visualization means, in real direction, of the acquisition window superimposed on a natural image of the landscape corresponding to the

  field of view of the camera (harmonization).

  an external control means for modifying

  manually the position of the acquisition window

  sition or the optical axis of the camera to bring it to a visible target in the image

  landscape, and a means of

  to put the system of

  automatic tracking to automatically maintain

  the window or the optical axis of the

  méra centered on this target means of orientation of a weapon mounted on the aircraft;

  a processor capable of using the signals

  stabilizing the direction of the optical axis of the

  méra TV orientation of the axis of the camera, and

  signals representing other parameters

  influencing the direction of fire, to generate signals of

of the weapon.

  2 - Apparatus according to claim the processor performs the position of the window 3 - Apparatus achieved by the fact that the application of control means of the automatic fire steering means 1, characterized in that a deviation measurement of the

in the field of the camera.

according to claim 1,

the processor generates

  two pairs of precession to the (x) gyroscope (s) as a function of the difference in the position of the attachment window with respect to a central position, in a sense suitable for bringing back the optical axis

  from the camera, driven by the gyroscope, towards a

  where the acquisition window is at its axial position.

  4 - Apparatus according to one of the claims

  I to 3, characterized in that it is Drevu an optical rangefinder mounted with the camera on a common support and receiving a beam according to the mCmeave coupled to the processor to provide a correction parameter of tiro

  - Apparatus according to one of claims 1

  to 4, characterized in that the rotational speeds

  the optical axis of the camera, evaluated by the precession currents of the gyroscope (s) are

  introduced into the processor to provide a para-

shot correction meter.

  6 - Apparatus according to claim 5, taken dependent on claim 4, characterized in that the processor is adapted to generate on the screen a particular visual symbol representing the point

future impact at every moment.

  7 - Apparatus according to one of the claims

  1 to 7, characterized in that the camera or its optical sighting system, or both at once are

  mounted on a platform hinged to the cardan for-

  view of orientation motors according to at least two axes,

  these motors being controlled by the direction detectors

the gyro device.