FR2524137A1 - SHUTTLE DRAWING SYSTEM WITH OBSERVATION GLASS CONTROLLED BY AN AUTOMATIC TRACKING DEVICE - Google Patents

Abstract

THE INVENTION CONCERNS A FIRE CONDUCT SYSTEM INTENDED TO BE MOUNTED IN PARTICULAR ON A HELICOPTER. A DEVICE 20 FOR AUTOMATIC TARGET TRACKING AND A MAGNIFICENT OBSERVATION SCOPE 10 ARE SLOWED TO ONE ANOTHER SO THAT, IN THE SEARCH PHASE, THE TRACKING DEVICE FOLLOWS THE ORIENTATION OF THE SCOPE AND THAT IN THE PURSUIT PHASE AUTOMATIC THE GLASS FOLLOWS THE PURSUIT DEVICE. FOR THE ALIGNMENT OF THE ORIENTATION OF THE SCOPE IN RELATION TO THE TRACKING DEVICE, A LASER EMITTER 56 CAN EMIT A LASER BEAM IN THE AXIS OF THE TRACKING DEVICE; THIS LASER BEAM REFLECTS ON AN OBSTACLE OR A TARGET AND IS RECEIVED BY A DETECTOR 54 CARRIED BY THE SCOPE. AN ECARTOMETRY CIRCUIT 52 PROVIDES ERROR SIGNALS REPRESENTING THE OFFSET OF THE LASER BEAM RECEIVED IN RELATION TO THE CENTER OF THE DETECTOR 54. THESE ERROR SIGNALS, RECORDED IN A MEMORY 42 IN THE RESET PHASE, ARE RETURNED AND TAKEN INTO ACCOUNT BY A CONTROL CIRCUIT 38, 40, 16 BETWEEN THE GLASS AND THE TRACKING DEVICE, IN THE TARGET SEARCH OR TARGET PURSUIT PHASE. PARALLAX ERRORS OR OTHER ERRORS IN THE ORIENTATIONS OF THE BEZEL AND THE TRACKING DEVICE ARE THUS ELIMINATED.

Description

At 22524137

  SHUTTLE DRIVING SYSTEM WITH A SERVICED OBSERVATION SCREEN

  BY AN AUTOMATIC TRACKING DEVICE.

  The present invention relates to a control system of

  shooting, and more specifically a self-aiming and tracking system

  target, particularly suitable for use on

  aircraft (including a combat helicopter).

  In a fire control system, an operator must first search for a target to be destroyed, notably by using a magnifying observation telescope which he guides in a site and on a bearing by means of a control stick.

  remote control acting on the orientation motors of the telescope.

  The operator sends to an automatic tracking device

  during this research phase or at the end of this phase, a forced orientation order of the tracking device along the axis of the telescope; then he decides to go into auto-tracking phase and sends to the tracking device a

  automatic orientation order on a marked target.

  In order to ensure the execution of this last point, the tracking system includes a sight optics

  image (video for example) of the target, and on the other hand

  deviation sensors operating for example by contrast or correlation, which locate the displacements of the image of the target in the field of the viske optics and which ensure the proper orientation of the tracking device to bring back this image of

target in the line of sight.

  Information on the direction taken by the

  Tracking signals are continuously transmitted, with possibly appropriate firing corrections, to a destruction weapon which therefore targets the target as long as it remains centered in the line of sight of the tracking device, and the operator

  can at any time send a firing order.

  It is desirable for the magnifying bezel to follow the movements of the tracking device when it executes an automatic tracking phase, so that the operator can use the telescope as a means of visual control of the correct execution of the pursuit. In case of loss of the target by the tracking device (passage behind a curtain of trees etc.), the operator must be able to regain control immediately or check that the tracking device catches the lost target alone (at the exit of the curtain trees by

example).

  On the other hand, when the operator targets a target with the telescope, and asks the tracking device to aim for the same

  target, the optics of the telescope and the optics of the

  the same point, without which the operator must perform an additional phase of checking or resetting the image given by the forward tracking device

to go into the prosecution phase.

  As the telescope is magnifying, even a small angle error between the two optics can have consequences

very annoying practices.

  However, several reasons contribute to create such errors and in particular the parallax error between the telescope and

  optics of the tracking device which, starting from two posi-

  similar but different, aim the same point, or angular errors due to the mechanical deformation of the structure of the helicopter that carries the fire control system.

  To solve these problems, the present invention

  installs a fire control system comprising an automatic tracking device that can be orientated in the field and in the field and provided with angular sensors that identify its orientation in the site and in the field, and a magnifying observation window provided with

  orientation engines in the field and in the field, and angular sensors

  The tracking device carries a laser illumination means capable of emitting laser radiation parallel to the axis of view of the device. The telescope carries a radiation detector. laser coupled to an associated deviation measurement circuit capable of providing a pair of error signals representing the difference in location and in bearing between the center of the detector (which represents the line of sight of the telescope) and the focal point of the laser radiation received by the telescope after reflection on an obstacle a memory is provided to receive and record these error signals in a registration phase during which the laser illumination means emits; an electrical circuit is provided to receive

  information from the angular sensors of the device

  suite and the telescope, as well as memory, and to provide

  to the orientation motors of the telescope, in a phase of

  automatic follow-up, control signals tending to make follow by the telescope the movements in site and bearing of the tracking device, with a correction corresponding to the signals

  error messages stored in memory during the registration phase.

  This registration makes it possible to overcome parallax errors and errors due to the deformations of the aircraft structure. It has the advantage of being able to use the laser range finder, which is often provided, as a means of laser illumination. in a fire control system (to develop ballistic firing corrections based on target distance), provided that the laser range finder actually emits parallel to the line of sight

  or even precisely along the axis of it.

  Other features and advantages of the invention

  will appear on reading the detailed description that follows and

  which is made with reference to the accompanying drawings in which: FIG. 1 represents a schematic diagram of the invention,

  Figure 2 schematically represents a possibility of

  arrangement of a laser emission means emitting in parallel with

  the optical axis of an automatic tracking device.

  The fire control system, mounted for example on a helicopter, comprises a certain number of elements which will be described only those which are necessary for the understanding of the invention. For example, not all visualization systems whose system is described will be described. fire control can be provided

  to help the operator or the pilot.

  Among the elements represented in FIG. 1, there is a magnifying observation telescope 10, orientable in

  in deposit by engines which are preferably engines-

  electromagnetically driven couples to avoid the presence of gears in the transmission of the movement The telescope 10 can also be gyrostabilized, that is to say that we apply

  steering control signals to these motors not directly

  but by means of gyrometers (single or integrating gyrometers or two-axis gyroscopes with tuned suspension) fixed on the telescope, these gyrometers having for axes

  sensitive rotation axes in site and in the field.

  To simplify the description of the invention, we have

  shown in Figure 1 that a directional orientation engine

  12 for the telescope; the whole description will be made

  only with reference to the bearing rotation axes, it being understood that two analogous independent circuit channels are required respectively for the orientation in

deposit orientation.

  The axis of rotation in the bearing of the telescope 10 is

  designated by reference 14 The axis of rotation in site would be

pendicular to the plane of the figure.

  An amplifier 16 provides control signals to the motor 12 (directly or via a control system).

  gyrostabilization) We will see here where these signals come from.

  An angular sensor 18 makes it possible to locate the orientation in bearing of the telescope; of course another sensor is

planned for orientation in site.

  Furthermore, an automatic tracking device 20 is another important element of the fire control system It is also orientable in site and in the field (engine

  orientation orientation 22) about an axis of rotation in

  24 and is preferably gyrostabilized, ie it receives control signals from an amplifier 26 not

  directly but through a gyrostabili-

  sation (not shown here) comprising integrating gyrometers or gyrometers or a tuned suspension gyroscope whose sensitive axes are the bearing axis of rotation 24 and an axis of rotation in a location perpendicular to the plane of FIG. Auto tracking device drive are

  preferably electromagnetic drive.

  orientation bearings (28) and in elevation (not shown) are provided on the tracking device 20 for locating its

orientation at any time.

  The tracking device has an objective for forming on an image sensor 30 the image of a target located in the field of view of that object; the optical axis of this objective is called the line of sight of the device 20 and is designated

by reference 32.

  The image detector 30, which can be a vidicon tube

  providing a video signal or a matrix of photoelectric detectors

  sibles, provides electrical signals representing the image of the field of view (and in particular the target pursued) to a deviation circuit 34 and possibly to display screens

(TV monitor etc).

  The deviation measurement circuit 34, which tracks the track, produces pitch and field deviation signals representing the difference between the position of the target in the image and a reference position (for example, the center of the picture); these signals are intended for the amplifier 26 which controls the orientation motors of the sighting device so as to bring the image of the target back to the reference position when it tends to deviate from it. The deviation measurement circuit can operate in contrast (the edge of the target image defines a contrast line whose position can easily be detected and compared to a reference position to generate deviation signals), or by image correlation: when the operator decides

  to go into the automatic tracking phase after manual

  When the target image is centered in the field of view, the image of this field obtained on the detector 30 is stored in memory as a reference image and the subsequent images are correlated with the image in memory, with a correlation function involving lateral and vertical shifts of the image, in order to define correlation peaks which make it possible to know the offset in

  site and location of subsequent images in relation to the initial image

recorded.

  A bearing deviation signal is transmitted by the circuit 34 to the amplifier 26 and an in-site deviation signal is provided in the unrepresented analogous orientation channel.

in site.

  The angular sensors (28 for the orientation in the bearing) send signals to a computer 36 which also receives other information, and the latter develops control signals for the direction of a shooting weapon, to give this weapon the same orientation as the aiming device (in phase of

  continuation), possibly corrected based on

  such as wind speed, distance from the target, type of shells, etc. The angular bearing sensor 18 of the telescope 10 and the angular bearing sensor 28 of the tracking device 20 are connected to the two inputs of a subtractor 38 which generates an error signal for aligning the orientations of the telescope and the device. This error signal is applied to an input of another subtracter 40 which receives on another input a so-called "harmonization error" signal coming from a

memory 42.

  The output signal of the subtractor 40, which corresponds to the difference between the orientations of the sighting axes of the telescope and the tracking device, affected by a harmonization correction, is directed either towards the input of the amplifier 26, in the target acquisition phase, either towards the input of

  the amplifier 16, in the automatic tracking phase.

  A switch 44 having a position "A" (for acquisition phase) and "P" (for tracking phase) is provided for this purpose to connect to the input of the amplifier 26, the output of the subtractor 40 ( acquisition position A), ie the output of the

  deviation measurement circuit 34 (P tracking position).

  Similarly, a switch 46 can direct to the input of the amplifier 16, either the signals from a remote control handle 48 in acquisition phase (position "A"), or the signals from the subtractor 40 in tracking phase (position Thus, in the target acquisition phase, the tracking device automatically follows the orientation of the telescope which is manually controlled, while in tracking phase the telescope automatically follows the tracking device's orientation who

  is controlled by its deviation measurement circuit.

  It can also be provided that the switch 44 has a third position, M, for directing to the input of the amplifier 26 signals from another set of

manual remote control 49.

  A third switch 50 is inserted between the input of the amplifier 16 and the switch 46, this switch ayalat a

  normal position "N and a so-called stall position" C ";

  N normal, the signals from the remote control handle 48 or the subtractor 40 are transmitted to the input of the amplifier 16; but, in setting position C, these signals are interrupted and other signals are supplied to the input of the amplifier 16 which are output signals of a deviation measuring circuit 52 whose input comes from a detector laser beam 54 carried by the

glasses 10.

  The detector 54 is advantageously of the four-quadrant type. It is placed on the bezel behind focusing optics and optionally selective filtering of a particular laser wavelength, so that if a laser beam reaches the axis or parallel to the axis of sight of the telescope, this beam falls in the center of the detector 54, whereas if the laser beam does not arrive quite parallel to the axis, it falls on a non-central portion of the detector , which then provides signals corresponding to the deviation in location and bearing from the center of the detector; these signals are processed by the deviation circuit 52 and

  applied to the input of the amplifier 16 but only in posi-

  so-called calibration (switch 50 in position C).

  The received laser beam comes from the reflection on an obstacle of a beam emitted by a laser illuminator 56 arranged to emit parallel to the line of sight 32 (or along this axis) of the tracking device; thus, the deviation measurement signals of the circuit 52 are an indication of the offset of the points targeted by the

  bezel and the tracking device.

  The deviation measurement signals of the circuit 52 are moreover applied to an input of a subtractor 58 which receives

  on the other hand the output of the subtractor 38; the exit from the subtract

  58 is applied, possibly through a switch 60 having a setting position C in which it is closed (and a normal open position), at the input of the memory 42 for

  record, during the calibration phase, the signal provided by the subtraction

  58 and which represents the harmonization difference between the telescope

and the tracking device.

  Finally, it is possible to provide a switch 62 for connecting the output of the memory 42 to the input of the subtractor 40 (position

  normal N: switch closed, setting position C: interrup-

open source).

  As for memory 42, if it must be ordered in

  writing, a control signal corresponding to

  in the stall phase during which the switches 50, and 62 are switched to position C. The circuit which has just been described with reference to FIG. 1 makes it possible to execute a target acquisition phase and a phase of FIG. In addition, the operator can perform a registration action of the orientation of the telescope in the following manner: he chooses an obstacle lying at a distance corresponding to a normal target distance and he points the tracking device 20 on this obstacle, preferably using the remote control handle 49 (switch 44

in position M).

  It then gives an order of passage in stall phase, which has the effect of switching the switches 50, 60 and 62 from the normal position N to the stall position C, and to emit laser radiation by the illuminator 56, then authorize

the writing in the memory 42.

  The telescope is then oriented so as to center if possible on the detector 54 the laser beam received after reflection on the target obstacle, and is stored in the memory

  a so-called harmonization error value corresponding essen-

  the angular difference which must exist between the angular sensors 18 and 28 so that the tracking device and the telescope aim at the same point (which in this case is the obstacle

targeted during the calibration phase).

  t This harmonization error takes into account parallax and other sensor positioning or adjustment errors, as well as deformation of the

the carrier helicopter.

  When switching to the normal position N switches, 60 and 62, this harmonization error is restored by the memory 42 and transmitted as a correction signal to the amplifier 26 in the acquisition phase or the amplifier 16

in the pursuit phase.

  FIG. 2 shows, as an indication, how the optical path of a laser beam can be arranged so that the tracking device 20 leaves the door tracking device parallel to the line of sight 32 of the latter, as a means of laser illumination, several reflecting mirrors, the actual laser illuminator, 66, being stationary and able to be offset A first mirror Ml, secured to a support movable in rotation around the axis of rotation in a site (68), returns the laser beam to a second mirror M 2, then a third mirror M 3, integral with the same support The beam received by M 3 is directed to a fourth mirror M 4 mounted on the optical sighting assembly (movable in site and in The laser beam emerges parallel to the line of sight 32 irrespective of the orientation in the field and in the bearing, particularly because the mirrors M1, M3 and M4 are placed so as to return the beam. beam be on the axis of r The optical elements of the tracking device 20 have not been shown to simplify the figure. 1 l

Claims (4)

CLAIMS.   A fire control system comprising an optical device (20) for automatic tracking of target orientable in location and in the field and provided with angular sensors (28) identifying its orientation in the field and in the field, a viewing magnifying glass (10) provided with orientation and bearing engines (12) and angular sensors (18) identifying its orientation at the site and at the bearing, characterized in that: a) the tracking device (20) carries means for laser illumination (56) emitting laser radiation parallel to the axis of view (32) of this device, b) the bezel carries a laser radiation detector (54) coupled to an associated deviation circuit (52) capable of providing a pair of error signals representing the difference in location and in bearing between the center of the detector (54) and the focusing point of the laser radiation received after reflection on an obstacle,   c) a memory (42) is provided for receiving and recording   record these error signals in a registration phase during which the laser illumination means (56) emits laser radiation, d) an electrical circuit (38, 40, 16) is provided for   receive information from the angular sensors of the   Tracking device and the telescope, as well as the memory, and to provide to the orientation motors of the telescope, in an automatic tracking phase, control signals tending to follow by the telescope the movements in site and in of the tracking device, with a correction corresponding to the error signals stored in memory during the registration.   System according to Claim 1, characterized in that the detector (54) is a four-quadrant detector placed behind a focusing objective and a filter   selective allowing the wavelength of the laser radiation to pass.   3 System according to one of claims 1 and 2,   characterized in that the signals from the deviation measurement circuit (52) are fed to the bezel orientation motors (12) so as to tend to orient the bezel in a direction such that the reflected laser beam   arrives at the center of the detector (54).   4 System according to one of claims 1 to 3,   characterized in that the electrical circuit comprises a   first subtractor (38) whose inputs are connected to the   angular drivers (18, 28) of the telescope (10) and the tracking device (20), and a second subtractor (40) whose inputs are respectively connected to the output of the first subtractor   (38) and at the output of the memory (42).