FR2665252A1 - Missile guidance system - Google Patents

Abstract

The guidance system comprises a sight; a manual control for generating control signals; a tracking device comprising an optical system for following a missile in flight in the field of view of the optical system of the tracking device, the said device being arranged to generate error signals representative of the radially offset position of the missile with respect to the projected axis of the tracking device, and being incorporated in a flight control channel comprising means of transmitting flight control signals to a receiver located in the missile such that a closed control loop is formed; means of injecting the manual control signals into the closed control loop; a common support for the tracking device and the sight; and a gyroscope mounted on the support and stabilising the direction of the projected axis of the tracking device.

Description

The present invention relates to missile guidance systems, and

  it concerns sighting arrangements

  and prosecution for such systems.

  In its broadest concept, the present invention relates to a guidance system for a guided missile

  and includes an optical viewfinder; manual control for generating

  to provide manual control signals in response to manipulation

  lation of said command by an operator; a tracking device comprising an optical system for tracking a missile in flight in the field of view of the optical system of the tracking device, said device being constructed and arranged to generate error signals representative of the radially offset position of the missile relative to to the projected axis of the tracking device, and being incorporated in a flight control channel comprising means for transmitting flight control signals to a receiver located in the missile to guide it in flight, so that a closed control loop is formed which includes an optical reaction path from the missile to the tracking device; means for introducing the manual control signals into the closed control loop; a common support which supports the tracking device and the viewfinder, the tracking device being constructed and arranged so that the direction of its projected axis is angularly movable relative to the support; and a gyroscope mounted on the support and arranged to stabilize and control the direction of the projected axis of the device

  continuation regardless of the movement of the support.

  Error signals from the tracking device can be used directly to provide flight control signals for missile transmission, while manual control is used to impose manual control on the gyroscope to force it to direct the axis of the tracking device The manual control can then be arranged to control the gyroscope so that it directs the axis of the tracking device, thereby introducing the manual control signals into the closed control loop on the floor

  of the poureuite device rather than independently of the operation

tracking device.

  Alternatively, the error signals from the tracking device can be used to set the gyros-

  cope in precession so that it forces the axis of the tracking device to follow the missile automatically while the error signals and the manual control signals are used together to form the flight control signals. In another form of the invention, the gyroscope is used to stabilize both the viewfinder and the device

  tracking, for use for example when the guidance system is mounted on a moving vehicle or aircraft.

  The gyroscope can be arranged to provide a signal representing the direction and speed of the angular displacement of the sight when setting a moving target immediately before launching a missile, means being present15 for introducing into the closed loop of commands, after launching the missile, a prediction signal corresponding to the signal supplied by the gyroscope immediately before launch to control the flight of the missile after launch. In such an arrangement, said means for introducing the prediction signal into the closed control loop includes a speed compensator signal generator connected to receive the signal supplied by the gyroscope immediately before launching said generator can also provide another signal to enter into the closed control loop,

  Another characteristic of the invention comprises the integration of the optical systems for the device for

  suite and the viewfinder in a single optical system which provides the field of view both for the tracking device and for the operator using the viewfinder, and whose axis is the aforementioned axis of the tracking device, the tracking device and the stabilizing gyroscope being connected in a quick response self-tracking control loop, so that the gyroscope directs the axis of the tracking device to keep it aligned with the missile being pursued, the exit tracking equipment also being provided to an integrator whose

  integrated output signal provides secondary control signals to control the missile during the post-preparation guidance phase, during which the manual control signals from manual control are superimposed

  ss to the secondary control signals During the missile launch and preparation phases, the system is switched to a condition in which the output of the tracking device is disconnected from the flight control signal transmitter 5 and the control output Manual is supplied directly to the torque motors of the gyroscope to drive the latter in order to direct (aim) the viewfinder towards a target. This arrangement is intended for applications

  such as a helicopter-borne weapon system, in which a gyro-stabilized optical sight is required

  to observe targets from a moving vehicle or aircraft No prediction command is provided in this arrangement. The figures in the appended drawing, given by way of non-limiting example, will make it clear. how the

  vention can be carried out. Figure 1 is a general view of a fire control unit for controlling a missile, in which a

  stabilizing gyroscope is an integral part of an automatic missile tracking device.

  FIG. 2 is a schematic block diagram of an arrangement of the control system of the unit of FIG. 1, in which the error signal from the tracking device is used directly to control the missile, and a control lever is used to change the pointing direction of the tracking device. Figure 3 is a longitudinal section of the schematic arrangement of the tracking device (2) and the gyroscope

  (3) of the fire control unit.

  Figures 4 5 and 6 are diagrams similar to Figure 3, showing the tracking device and the gyroscope in different operating states for the system of Figure 2.35 Figure 7 is a diagram similar to Figure 2 of a variant control system in which the error signal from the tracking device is used to direct the tracking device through the gyroscope to point towards the missile, and control signals are

  generated by the tracking device and the control lever

  command to direct the missile. FIG. 8 is a diagram of a third embodiment of the invention comprising an optical viewfinder and a gyroscope stabilized tracking device, the optical elements of which are integrated with those of the viewfinder, the single gyroscope

  stabilizing both the tracking device and the viewfinder, and the system being shown in the guidance phase. Figure 9 is a diagram of the system of fi-

  gure 8 but representing the conditions in the pre-launch and missile preparation phases.

  Referring to Figure 1, a telescope sight 1 and the integrated set of a tracking device 2 and a stabilizing gyroscope 3 are mounted together on a case 4 which contains all the necessary electrical equipment. The telescope 1 and the tracking device 2 are generally aligned, and the tracking device 2 and the gyroscope 3 are integrated so that the direction, relative to the case, of the optical axis directed towards the front of the device20 tracking is variable and is only determined by the position of the gyroscope steering wheel, the direction of the optical axis being controlled by an optical element fixed to the gyroscope steering wheel A handle 5 is fixed to the case 4 and it includes a lever control 6 to provide control signals The handle 5 also carries a firing trigger 7 so that an operator can fire a missile at the appropriate time All equipment is constructed in such a way that an operator can use it many ways, either supported on the ground by means of a support structure, or held in the hand A goal30 of the gyroscope 3 is to ensure that, whatever the support of the system, the projected optical axis of the tracking device 2 is stabilized in space and does not respond to the angular movements of the complete material Another aim is to act as a device for directing the projected optical axis of the tracking device by means of applied control signals to the precession torque motors contained in the gyroscope, and at the same time stabilizing the projected optical axis of the tracking device, when all the material is subjected to an angular movement A third aim of the gyroscope 3 is to act as

  device for measuring the angular velocities of all the material

  riel at a time when stabilization and steering action, as described above are not required, The tracking device 2 is of the type

  both an arrangement of photoelectric detection cells, with a diffusing screen on which a real image of a fire

  (or flag) carried by a missile 8 is concentrated at the focus by the optical system of the device 2, said device for

  sequence producing electrical signals corresponding to the coordinates of the position of the image of the missile with respect to the electrical center or reference point of the screen, which is

  set to zero to be on the optical axis of the tracking device These signals are therefore representative of the direction and the quantity by which the missile is offset15 from the optical axis projected towards the front of the tracking device. These signals are appropriately modified by electrical equipment.

  stick contained in the housing 4 and, consequently, produce control signals which are transmitted to the missile 8 by a rear cable 9 The control signals are received by a receiver 20 in the missile 8 and are used to control the operation of the devices of actuation used to steer the missile.

  Other types of tracking devices can also be used. Referring also to FIG. 2, this represents

  schematically presents an arrangement of the control system incorporated in the apparatus of FIG. 1 In use, before launching the missile, the operator first directs the aiming device 1 towards the target by means of the handle 5, and follows the target by using a sighting mark in the device 1.3 o by directing therefore also the tracking device 2 approximately towards the target When it is necessary to launch a missile, the operator depresses the trigger 7 of firing while following the target with the viewfinder The resulting firing signal is used to start and release the gyroscope 3 which, operating in angular speed measurement mode, transmits a signal proportional to the target angular speed to a target speed compensation generator 10 After a short instant, the missile is then automatically launched and an automatic switch causes the gyroscope 3 to start operating in stabilizing mode, the axis opti that of the tracking device 2 being

  consequently stabilized in the direction pointed at the position of the target at the time of launching the missile After launching, the tracking device 2 detects the fire (or flag) of the missile and generates signals representing the radial direction and distance of the position of the missile in relation to the sta-

  tracked from the tracking device These signals pass to a shaping unit 11 where they are modified and sent to a transmitter 2 which in turn provides control signals to the missile 8 by the 10 c Rear cable 9 Deviations 13 of the missile 8 in flight relative to the projected axis of the tracking device are detected by the latter and the compensation corrections are introduced into the transmitter 12 by the error reading system of the tracking device, so that the missile 8 is controlled by 15 the tracking device to stay on the axis of the latter, After launch also, the target speed compensation generator sends a signal, representing the angular speed of the line of sight at the time of firing, to a shaping unit 14 which modifies the signal and passes it to the motors with precession torque in the gyroscope 3 so that the optical axis of the tracking device 2 begins and continues to rotate at an angular speed corresponding to that of the viewfinder, which was established when setting the missile before launching Furthermore, the generator 10 produces signals which pass to the unit 11 for forward transmission to the missile, These signals correct a natural tendency of the missile C to drag behind the axis of the tracking device when the latter moves, During the flight of the missile, the operator observes by the viewfinder 1, the positions of the target and the fire (or flag) of the missile and it can maintain the flight path

  of the missile along its line of sight towards the target by means of the control lever 6, without necessarily rotating the whole case 4, The movement of the control lever 6 provides an electrical signal EF which is modified by the setting unit in form 14 and is sent to the motors with precession torque in the gy-

  stabilizing roscope 3 to direct the optical axis of the tracking device so that the missile's light (flag) and the target are superimposed in the field of view of the sight 1, The lever

  control 6 thus provides a main directional control

  missile blade superimposed on the automatic control by the

  positive tracking and forecast command by the general

  Target speed compensation rator.

  After launching the missile, it may be necessary for the operator, during contact with the target, to rotate the entire fire control unit so as to keep the target in the sight of sight 1 This rotation after launch n influence the direction of flight of the missile by

  following the stabilizing influence of the gyroscope 3.

  Figure 3 shows the tracking device 2

  and the gyroscope 3 which together occupy a shoemaker 30 The gyros-

  cope 3 is a reusable, spring-loaded, light-weight, two-degree-of-freedom instrument comprising a rotor 31 mounted in an assembly 32 with universal joints, with an assembly 33 of torque motors and sockets, including the peripheral motors to torque can be used to position the point of

  internal gimbal of the assembly 32 with respect to orthogonal axes

  nal (azimuth and elevation), The torque motors of the set 53 have the small angle magnetic sockets integrated therein A set 34 of tension spring with a winding winch 35 and a bunch of overtaking and sequence gears 36 be coupled to rotor 31 by means of a clutch

  outlet 37 controlled by an outlet outlet and release pin 38

health of the back of the boot maker 30.

  The tracking device 2 in the extreme

  anterior half of the shoemaker 30 includes a system 39 of lenses

  of objective which contains in its center the whole 40 ti detector

  positive tracking, This set includes a group 41 of detective

  static slitters installed in front of a diffusing screen 42 and coupled to an amplifier 43, The system 39 has an optical axis-44 * A mirror 45 with a planar reflecting surface is mounted in the anterior end of the rotor 31 so that the reflecting surface 46 either perpendicular to the axis of rotation of the rotor 31 and is directed towards the diffusing screen 42 The reflecting surface 46 of the mirror 45 is placed at a distance equal to

  half the rear focal length of set 39 from

  shooting of the screen 42, so that a real optical image of a distant object seen by the tracking device is formed by the assembly 39 of lenses on the diffusing screen 42 after reflection by the mirror 45, We will describe now briefly the operating principles of the optical system of the tracking device with reference to FIGS. 4 to 6,

  Figure 4 shows the situation for operation.

  basic ment of the tracking device while the mirror 45 is perpendicular to the axis 44 of the tracking device, that is to say that the gyroscope is either engaged or not deflected, The set 39 of lenses and the mirror 45 produce on the diffuser screen a

  image A 'of a missile at A which is on the projected axis 44 of the dispo-

  tracking target, image A 'being in the center of the screen 42.

  A missile in B, which is offset from the projected axis 44 of the tracking device in its image in BI, offset from the center relative to the screen 42, and the edge of the screen 42 therefore establishes the angle @ max

  limits the deviation of the axis of the tracking device field.

  Image B '(outside center) on screen 42 will generate a signal by the detector, which is linked to the coordinates outside center of image B', and this signal is used as a request signal by which the missile in B is commanded to return by flying to position A on the projected axis, Figure 5 shows the situation when the housing of the tracking device has moved by an angle O max

  as a result of a launching problem or a wandering goal.

  The rotor 31 of the gyroscope and the mirror 45 have remained oriented in the direction of origin in space. The main ray of light leaving the missile A will strike the mirror 45 perpendicularly, and the image of the missile therefore remains at A 'in the center of

  detector screen 42 The detector produces no error signal

  so the missile is not asked to change its position in space In other words, the optical axis of the tracking device has been stabilized in space by the gyroscope 3 and

  the mirror 45 against the effect of the disturbances of the shoemaker 30.

  Figure 6 shows the situation when the mirror 45 is driven away from the axis by a signal from the control lever 6 and arriving at the torque motors, as described with reference to Figure 2 An off-axis missile in B will have its image at B 'which is now in the center of the screen 42, so that the detector 41 produces no signal It follows that a missile at A which responds to the signal from the detector will be driven off axis towards B as the mirror moves, We see that the gyroscope D has three distinct modes of operation:

  a) it is released at the start of an adjustment operation on

  ble before launch, and fulfills the function of a speed gyroscope The deviation of the case 40 of the gyroscope and of the tracking device around the rotor 31 stabilized in space is measured

  through the small angle plugs, and the signal thus produced is amplified

  relied on and used to excite the peripheral torque motors, which bring the rotor into alignment with the case 40 The rotor is therefore effectively held on the axis with the flight control unit, but the signal on the sockets gives a measure of the torque required to keep the rotor in alignment with the housing and, therefore, the speed at which the tracking device rotates while following the moving target, This signal is processed to provide target speed compensation as described next to the Figure 2; b) when the torque motors are disconnected from the sockets, as happens when the missile is launched, the rotor is free to keep a fixed reference in space, and fulfills a normal stabilizing function for the axis of the device prosecution; and c) if a signal is applied to torque motors from a source

  any other than the sockets, the rotor will be deflected at a speed

  is proportional to this signal, but will continue to perform a stabilizing function against the movement of the unit.

  fire control, In practice, the control lever 6 in the system

  missile guide tem is used to drive the end torque motors to provide position changes in the

  rotor, as described above.

  A variant arrangement of the control system -: and of the operating principle of the apparatus of FIG. 1 is shown diagrammatically in FIG. 7 In this arrangement, the output of the tracking device 2 is used to direct the gyroscope 3 and , consequently, the projected optical axis of the device 2, so as to align the axis of the tracking device with the fire (or flag) of the missile observed by the viewfinder In addition, the signals of the tracking device, which represent the angular speed requests from the gyroscope 3, are sent to an electrical integrator 15 which converts the angular speed signals into an integrated signal proportional to the angle which the axis of the tracking device has turned. This integrated signal is sent to the unit formatting 11 and converted therein to request signals for forward transmission to the missile 8 The effect of this integrated signal is to command the missile 8 so that it moves towards a lig target sight originally determined by the initial direction of the axis of the tracking device 2 Said axis remains pointed at the missile fire because of the flight control loop existing between the tracking device 2 and the gyroscope 3 and, while said axis follows the fire of the missile and returns to its original direction, the signal of the integrator

  returns to zero In this arrangement, the generator 10 of

  target speed thinking works as in the previous arrangement, except that the signal delivered to the gyroscope 3 does not pass through the shaping unit 14 Signals coming from the control lever 6 pass to said unit 14 where they are modified and sent directly to the shaping unit 11 as main control signals for forward transmission to the missile 8 The movement of the lever 6 now controls the missile so that it moves relative to the line of sight of the target , the axis of the tracking device 2 being obliged to follow the missile until the output signal of the tracking device which has passed through the integrator 15 is sufficient to cancel the signal

  of the control lever So in this variant of the system, the

  Control panel 6 also provides a main directional control of the missile 8, superimposed on the automatic control by the tracking device 2 and the prediction control by

  the target speed compensation generator 10.

  In these two arrangements, the flight of the missile is not affected by any movement of the complete fire control unit held in the hand (or guided in the hand) after launch, as a result of the stabilization effect in space

of the gyroscope.

  The two arrangements include a main new characteristic of the invention, that is to say the compensation

  prediction for moving target speeds Before launch

  cement, we use the gyroscope to measure the approximate angular speed of the target as it is followed by the viewfinder, and this speed is automatically maintained imposed on the tracking device after launch, This characteristic is present to help very short engagements distance

of intersecting targets.

  The third embodiment of Figures 8 and

  9 relates to the application of the invention to a communication unit

  fire command for a helicopter-borne weapon system.

  The main differences with the first two modes of

  reading come from the association of the system with a viewfinder

  gyroscope stabilized optics, which is necessary for observing

  Targeting from the mobile helicopter.

  In this case the optical elements of the

  tracking are integrated into the optical viewfinder and the gyroscope

  read both the viewfinder and the tracking device Only one control lever is used at a time to steer the viewfinder and,

  during engagements, to command the missile.

  The general arrangement during the guiding phase is illustrated schematically in Figure 8.

  tracking 2, the gyroscope 3 and a stabilizing mirror 3 A are re-

  linked in a fast self-tracking loop This keeps the axis of the dis-

  tracking positive (which is also the optical axis of the sight) aligned with the missile's fire and the missile in the center of the optical field of view presented to the operator by the optical system

  integrated, any tendency of the missile to drift means that the gyros-

  cope follows and a signal appears at the output of the integrator, this signal representing the measured drift of the missile This results in a command being applied to the missile so as to eliminate 1 drift, Movement correction movements of the missile and tracking device / sight set

  can be carried out by operating the control lever 6.

  The operator uses the missile, which is held in the center of its sight, as a target mark and keeps it on the target in

manipulating the control lever.

  The layout before launch and during preparation

  ration is shown in Figure 9 Before launch, the same control lever 6 is connected to the torque motors of the gyroscope 3 and is used by the operator to place the viewfinder on the target using an illuminated sight mark - in the viewfinder Immediately after launch, an Si interrupter closes and open loop commands can be sent by this switch to the missile to bring it towards the line of sight of the target which, in some systems of missile, can be found at great angles relative to the axis of the body of the helicopter on which the missiles are mounted When the missile enters the field of view of the tracking device / sight assembly which at the start, works in preparation mode

  at wide angle, a switch 52 closes and commands come from

  from the tracking device 2 are sent to the missile to bring it on the axis of the guidance device During the preparation phase, the operator continues to aim the sight on the target

  using the illuminated aim mark and the control lever.

  When the missile has been prepared, the guidance device changes to pass its precise narrow-field guidance mode, the mark

  aiming sight goes off and the system is switched to the agency-

  Figure 8, In this system, the target speed compensation characteristic described with reference to Figure 2 is not necessary because, by following the target with the illuminated aiming mark, the operator establishes the required position of the lever. control to give the correct line of sight speed and, apart from small adjustments, the same position of the

  command will be used during the guidance phase.

Claims (6)

  1. Guidance system for guided missile, characterized in that it comprises an optical sight; manual control for generating manual control signals in response to manipulation of said control by an operator; a tracking device comprising an optical system for tracking a missile in flight in the field of view of the optical system of the tracking device, said device being constructed and arranged to generate error signals representative of the offset position ra-10 dialing the missile relative to the projected axis of the tracking device, and being incorporated in a flight control channel comprising means for transmitting flight control signals to a receiver located in the missile to guide it in flight, so that a closed control loop is formed which includes an optical reaction path from the missile to the tracking device; means for introducing the manual control signals into the closed control loop; a common support which supports the tracking device and the viewfinder, the tracking device being constructed and arranged so that the direction 20 of its projected axis is angularly movable relative to the support; and a gyroscope mounted on the support and arranged to stabilize and control the direction of the projected axis of the tracking device independently of the movement of the support. 2. System according to claim 1, characterized in that the optical systems of the viewfinder and of the tracking device are integrated into a single optical system which provides a common field of view for the tracking device as well as for the operator looking through. the viewfinder, the axis of the integrated optical system comprising the axes coinciding with the tracking device 30 and the viewfinder, and in that the gyroscope is arranged to stabilize and adjust the direction of the projected axis of the integrated optical system, 3, System according to claim 1 or 2, characterized in that the error signals of the tracking device are used directly to provide the flight control signals. 4. System according to claim 1 or 2, characterized in that the error signals of the tracking device are   used to have the gyroscope direct the axis of the dispo-   1-3 tracking track in order to maintain said projected axis aligned with the guided missile.   , System according to claim 4, characterized in that the error signals of the tracking device are placed in precession on the gyroscope to direct the axis of the tracking device so that it follows the missile in flight, the tracking device error signals also being used to provide the flight control signals. 6, System according to claim 5, characterized in that it comprises means for integrating the error signals of the tracking device and for using the integrated signals to form the flight control signals. 7. System according to claim 6, characterized in that the integrating means are arranged so that the integrated signals are representative of the   deflection of the missile from the initial line of the pro-   thrown from the tracking device, so the effect of the flight control signals is to move the missile towards the alignment with said line.   8 System according to any one of the claims.   tions 1 to 7, characterized in that the gyroscope is arranged to provide a signal corresponding to the directional speed of angular displacement of the sight during the pursuit of a moving target immediately before the launch of the missile, means being present to introduce into the closed control loop, after launching the missile, a prediction signal corresponding to the signal supplied by the gyroscope immediately before launching,   to control the flight of the missile after launch.   9. System according to claim 8, characterized in that said means for introducing the prediction signal   in the closed control loop are activated after launching   ment of the missile to put the gyroscope into action so that it directs the axis of the tracking device in one direction and   at an angular speed corresponding to that of the immersive viewfinder diat before launch,   10. System according to claim 8 or 9, charac-   terized in that said means for introducing the signal   prediction in the closed loop command include a general   speed compensation signal generator connected to receive   the signal from the gyroscope immediately before launch.   11, System according to claim 9 or 10, charac-   terized in that it comprises means for introducing into the closed control loop an additional signal from the   speed compensation generator output.   12. System according to any one of   Claims 8 to 11, characterized in that the gyroscope comprises   torque motors through which the axis of the gyroscope rotor can be steered in response to the supply signals to torque motors, said motors being provided with electromagnetic engagement means for measuring the deviation or the deflection speed of the axis rotor.   13. System according to any one of the claims.   tions 1 to 12, characterized in that the means for introducing the manual control signals 2 le into the closed control loop are arranged to use the manual control signals for   fine-tune the gyroscope to direct the axis of the device pursuit.   14, System according to any one of the claims   1 to 13, characterized in that the tracking device and   the gyroscope are mounted in a common case, the rotor of the gy-   roscope being mounted by means of a universal joint arrangement   behind the optical system of the tracking device in the box   tier, the tracking device having a rear-facing detector screen positioned behind its objective lens assembly, and in that the gyroscope carries a mirror mounted so that its reflecting surface is kept radial with respect to the axis of the rotor and is directed towards the detector screen of the tracking device, the mirror being arranged to reflect by reflection, on said screen a real optical image provided by the optical system of the tracking device, of the scene in the field of view in front of the optical system of the tracking device.   15 System according to claim 14, characterized in that the distance from the reflecting surface of the mirror to the screen of the tracking device is equal to 4 to half the rear focal length of the set of objective lenses   of the optical system of the tracking device. 16 2665252   16. System according to any one of the claims.   1 to 15, characterized in that the common support for the viewfinder and the tracking device is a vehicle or an aircraft moving.