Abstract: A position-controlled actuator includes a motor supplied with power by a power supply circuit controlled at least by an error signal. A speed reducer converts rotary movement of the motor into linear movement over a given travel. An output sensor indicates the position of the actuator and an error signal computation circuit compares a commanded position of the actuator to a calculated position. The output sensor supplies a binary position signal taking two different values according to the position of the actuator relative to its mid-travel position.

Abstract: An actuator suitable for autopilot control of a helicopter tail rotor comprises a direct current motor, a non-reversible gearbox, a speed reducer driving an output shaft, a friction device disposed between the non-reversible gearbox and the speed reducer and a friction exceeded sensing device adapted to cut off the supply of power to the motor.

Abstract: An autonomous kinematic measurement system for helicopters is disclosed. A helicopter comprises a lifting rotor, an anti-torque rotor, first means to control the cyclical pitch and the collective pitch of the rotor and second means to control the pitch of the anti-torque rotor. The system comprises means to measure the helicopter's ground speed, means to measure the longitudinal cyclical pitch of the lifting rotor blades, means to measure the lateral cyclical pitch of the lifting rotor blades, means to measure the collective pitch given to the lifting rotor blades, and means to measure the pitch of the anti-torque rotor. An inertial unit, provided with ancillary computing means, uses a direction signal and a helicopter attitude signal corresponding to the longitudinal acceleration signal and lateral acceleration signal of the helicopter's ground speed signal to establish the helicopter's longitudinal and lateral airspeed values, following a determination of the coefficients .alpha.,.beta.

Abstract: The invention relates to a signal generator with programmable variable frequency and comprises a reference oscillator, a first frequency divider receiving the signal emitted by the reference oscillator and delivering an instantaneous frequency signal (FS). A control chain for said first frequency divider comprises a second frequency divider and a first programmable integrator system, which controls the first frequency divider. A control chain for the second frequency divider comprises a second integrator system receiving the output signal (FS).

Abstract: A device for manual or automatic opening of an aircraft safety equipment box includes a pin fixed to the box door, a pivotable hook engageable with the pin, and a resilient return assembly associated with the hook. The return assembly has a main spring urging the hook to a disengaged position and a locking lever pivoted about the same axis as the hook. In its locked position the lever abuts and holds the same part of the main spring as holds the hook in its engaged position. In the release position the lever frees the main spring to drive the hook to disengage it from the pin. The return assembly further has a secondary spring for returning the lever to its release position and the hook to its engaged position. The return assembly includes a release plate locking the lever in its locked position. Displacement of the plate causes the hook to disengage from the pin.

Abstract: The mirror comprises a cellular structure core having a stack of plies each constituted by fiber-containing polymerized resin fixed on at least one face thereof, with a reflecting surface being made on the stack, and with the fibers in each ply extending in one direction only. The invention enables ultralight-weight mirrors to be made having excellent mechanical properties.

Abstract: Equipment for providing protection against drowning, in particular for use by the driver of a motorized water vessel, the equipment comprising:a supply (110) of air under pressure, feeding a regulating pressure expander (130, 140);a face mask (210) including a breathe-in valve (211) and a breathe-out valve (212); andswitch means (160) for selectively connecting the breathe-in valve of the face mask either to the regulating pressure expander or else to the atmopshere, said switch means being constituted by an electrically controlled valve permanently powered via a safety inertia switch, such that the breathe-in valve of the face mask is connected to the surrounding air so long as the electrically controlled valve is fed with electricity, and that in the event of the inertia switch interrupting the supply of electricity to the electricity controlled valve, because of the vessel being subjected to a shock, the breathe-in valve of the face mask is immediately switched to the regulating pressure expander.

Abstract: A helicopter is provided with a lift rotor (Ros), a tail rotor (Rac), first control means for the longitudinal (Pcx) and lateral (Pcy) cyclic pitch of the lift rotor and second control means for the pitch (Pac) of the tail rotor. The parameters such as the longitudinal cyclic pitch (Pax), the lateral cyclic pitch (Pcy), the longitudinal acceleration (Vx) and the acceleration of the helicopter (Vy) as well as the collective pitch (Pcol) of the lift rotor (Ros) and the pitch of the tail rotor (Rac) are measured. The longitudinal (Vax) and lateral (Vay) speed of the helicopter with respect to the air are determined from a biunivocal function of the measured values, particularly in linear combination.

Abstract: A device for half-opening the door of a box containing safety equipment such as oxygen masks, said device enabling said door to be held in a partially open position for inspection purposes without releasing the safety equipment, said device being constituted by a half-opening member hinged to said door about a transverse axis, said half-opening member having an operating portion on one side of said axis and a latching portion on the other side of said axis, said operating portion, when in a normal position, closing an associated opening through said door, and said latching portion, when in an inspection position, co-operating with a latching member fixed inside said box.

Abstract: The assembly comprises a laser emitter (100), localization means (200) for providing data on the angle between a target and a projectile, an aiming block (300) enabling an operator to aim at the target optically, and collimator means (400) enabling the operator to center the target in the field of view. In accordance with the invention, harmonization means (500), e.g. a crossed-prism deflector (501, 502) interposed between the collimator means and the aiming block, are provided to adjust the angular orientation of the collimation direction in such a manner as to cause said direction (O.sub.7 D.sub.7) to coincide with the reference (A.sub.2 B.sub.2) or aiming (A.sub.1 B.sub.1, C.sub.1 D.sub.1) direction, i.e. with the direction corresponding to the real aiming and designation direction to the target, and also with the localization direction (J.sub.3 K.sub.3), i.e. the direction in which the localization means sees the designated target.

Abstract: A method of processing a video image to track a bright spot and to protect said tracking from interference from other bright spots to protect said tracking from interference from other bright spots. In order to avoid a main spot (LP) from being lost by interference from decoy or secondary spots (LS) in a digitized video image (FM), the main spot is surrounded by a detection ring (CD) which is concentric with a processing window (FT) which fits closely round the main spot. When a decoy spot (LS) is detected in the detection ring, it likewise has a processing window (FT') and a detection ring (CD') assigned thereto in order to isolate it and to follow its trajectory. When the two spots come into contact, the tracking of one of said spots is interrupted. After the two spots move apart, a coherence test is performed to determine which of the spots is the main spot, and tracking continues, thereafter, with the main spot.

Abstract: In order to scan a relatively small window (F) in the image zone (ZI) of a charge transfer device, a series of prior transfers (B.sub.1, B.sub.2, B.sub.3) are performed moving from the image zone to the memory zone (ZM) to move the leading edge of the window until it is adjacent to the output shift register (RD). The lines of the window may then be read conventionally (B.sub.4) omitting any reading of the lines that come before or after. This considerably reduces the delay (between steps B.sub.1 and B.sub.4) between image acquisition and signal processing, without altering the frame frequency which remains fixed at 50 Hz, for example.

Abstract: A gyroscope constructed in accordance with the present invention includes a flywheel (220) which can oscillate with at least two degrees of freedom about a central position in which the flywheel axis is aligned with the axis of a drive shaft (200), the flywheel being held radially and rotated relative to the body (100) of the apparatus. The gyroscope also includes a set of electrodes (101 to 104) for electrostatically controlling the position or for detecting the position of the flywheel. The electrodes are fixed relative to the body and face corresponding conducting surfaces of the flywheel. In accordance with the invention, the gyroscope further includes a rigid spinning casing (250) which encloses the flywheel in such a manner as to interpose a dielectric surface between the corresponding conducting surfaces of the flywheel and each electrode, the casing being fixed to the flywheel drive shaft but not having any degrees of freedom in oscillation relative to the body other than being free to spin.

Abstract: A flexibly suspended gyroscope apparatus comprises a fixed body (100), a rotary drive shaft (200) supported in said body, and a flywheel (220) mounted on said drive shaft by a rotary joint (222). The joint serves to retain the flywheel radially and to transmit rotary drive thereto, while leaving said flywheel free to oscillate with two degrees of freedom about a central position in which the axis of the flywheel is aligned with the axis of the drive shaft. The flywheel is also free for axial translation with one degree of freedom. Axial support means (101, 102, 103, 104) are provided for applying an axial force to the flywheel by electrostatic or electromagnetic induction, and axial position detector means are provided for detecting the axial position of the flywheel, said support means being servo controlled by said detector means to maintain the flywheel in a predetermined axial position.

Abstract: An electrostatic motor is constituted by a capacitor (10) having relatively movable electrodes (11, 12) separated by a variable gap (13). The control circuit includes a DC source (60) which is servo-controlled to current measurement means (20) and integrator means (30) for calculating the charge on the capacitor plates and for maintaining said charge constant (Q.sub.0). By applying servo control to keep the charge constant, the force on the plates is independent of the variable value of the gap (14). The charge is preferably on/off switched with a pulse width modulation ratio that is a function of the force which is to be applied.

Abstract: The arrangement is of the type comprising: an optical sight (200) combined with an afocal opto-electronic unit (300).According to the invention the opto-electronic unit is located in front of the entry window (210) of the optical sight and the light rays emitted by a reticle (250) are guided from the optical sight (ABC) thus passing through its entry window (210), then towards the exit window (320) of the opto-electronic unit (CDEFG) in order to make the rays emitted by the reticle follow the same optical path (GHIJ) as the rays emitted by the object to be observed (400).The angular deviations produced by the addition of the opto-electronic unit are thus compensated for.In order to measure the magnification produced by this addition, the reticle (251,251') is split by a known value (1) the distance (1') between the images of this split reticle is then measured by a row of diodes (280), (FIG. 2).

Abstract: A spherical indicator for use on board an aircraft comprises one or more pointers supported by members which are mounted to rotate in front of a sphere of the indicator. The member which supports a pointer is mounted to rotate about an axis which passes through the center of the sphere.

Abstract: The invention relates to missile guidance and provides a method and system for guiding one or more missiles on to one or more targets. Aim on the targets and missiles is taken by means of two electro-optical pick-ups having a switchable field of view and supported on a stabilized and orientable platform. The pick-ups provide images displayed on screens and the corresponding video signals are processed by deviation measuring circuits which form tracking windows around the image of the targets and the missiles and determine their coordinates, the latter being addressed to a computing unit which generates guidance and steering commands transmitted to the missiles.Application to the automatic guidance of missiles fired as a salvo from an anti-tank helicopter.

Abstract: A gyroscope comprises a rotor driven by a motor shaft through the intermediary of an intermediate ring connected to the motor and to the rotor by torsion bars at 90.degree. with respect to each other and precession motors for applying to the rotor, precession torques in planes containing the axis of rotation of the drive shaft. Precession motors are fixed electromagnets exerting a force of attraction on the rotor. A system for supplying current to the electromagnets is provided, reacting to a control by an electrical control signal, this system having a response such that the attraction torque exerted by a pair of diametrically opposed electromagnets is a linear function of a parameter of the signal for controlling the current applied to the electromagnets.The gyroscope may have an elastic suspension and be intended to rotate at high speed.

Abstract: The invention relates to the aiming of an optical illuminator on a target. The direction in which is seen the maximum light of the illuminator reflected by the target is detected, the angle formed by this direction and the direction of sight is measured and the result of this measurement is employed for controlling an orientation of the optical axis of the illuminator or of the optical axis of the sighting system, with the result that the direction in which is seen this maximum coincides with the optical axis of the sighting system. The invention is particularly applied to the sending of a moving body, provided with an optical, self-directing system, onto a target.