US3677134A

US3677134A - Gunnery control device for turret-mounted firearm

Info

Publication number: US3677134A
Application number: US23845A
Authority: US
Inventors: Jacques Paul Robert Maximi; Andre Bernard Maurel
Original assignee: Etat Francais
Current assignee: Etat Francais
Priority date: 1969-03-31
Filing date: 1970-03-30
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18
Also published as: DE2015326A1; FR2038816A5; SE378299B; GB1309793A

Abstract

Device to give accurate information as to angular velocity of the turret and automatic interpolation of the tachometric and ballistic corrections dependent on speed, target distance and ballistic parameters in both the laying and sighting of the weapon so that the line of sight is held on target without any personal manipulation by the gun controller. A turret is driven through a reduction gear box by a hydraulic engine controlled by a servo valve. There is connected to the turret through the reduction gearbox a device including a stator and a rotor, the relative shift between the stator which is connected to the turret and the rotor being used to control in part the servo valve controlling the hydraulic engine driving the turret. The aforesaid rotor is connected to a cylinder driven by a rotating disk at a controllable variable speed inasmuch as the roller is coupled to the disk by displaceable balls which are displaceable diametrally along the disk. The position of the balls between the roller and the disk is controlled through a servo motor in turn controlled by a potentiometer responding to the laying device for the associated gun. A potentiometer indicates the position of the balls between the disk and roller and this information is fed to a potentiometer which is also provided with a signal representing the time required for a projectile to travel to a specific target. The resulting signal is fed to a reticle control in the associated sighting device and a signal is generated indicating the correction of the reticle for purposes of further controlling the aforesaid servo valve.

Description

Unite States Maximi et al.

151 3,677,134 51 July 18, 1972 [s41 GUNNERY CONTROL DEVICE FOR TURRET-MOUNTED [72] Inventors: Jacques Paul Robert Maxim], Tarbes; Andre Bernard Maurei, Aureilhan, both of [21] Appl.No.: 23,845

[30] Foreign Application Priority Data March 31, 1969 France ..6909569 [52] US. Cl. ..89/4l E, 89/41 H [51] Int. Cl. 413 3/22 [58] Field of Search ..33/49 B; 89/41 E, 41 EA, 41AA,

Primary ExaminerStephen C. Bentley I Attorney-Waters, Roditi, Schwartz & Nissen 57] ABSTRACT Device to give accurate information as to angular velocity of the turret and automatic interpolation of the tachometric and ballistic corrections dependent on speed, target distance and ballistic parameters in both the laying and sighting of the weapon so that the line of sight is held on target without any personal manipulation by the gun controller.

A turret is driven through a reduction gear box by a hydraulic engine controlled by a servo valve. There is connected to the turret through the reduction gearbox a device including a stator and a rotor, the relative shift between the stator which is connected to the turret and the rotor being used to control in part the servo valve controlling the hydraulic engine driving the turret. The aforesaid rotor is connected to a cylinder driven by a rotating disk at a controllable variable speed inasmuch as the roller is coupled to the disk by displaceable balls which are displaceable diametrally along the disk. The position of the balls between the roller and the disk is controlled through a servo motor in turn controlled by a potentiometer responding to the laying device for the associated gun. A potentiometer indicates the position of the balls between the disk and roller and this information is fed to a potentiometer which is also provided with a signal represent ing the time required for a projectile to travel to a specific target. The resulting signal is fed to a reticle control in the associated sighting device and a signal is generated indicating the correction of the reticle for purposes of further controlling the aforesaid servo valve.

6 Claims, 2 Drawing Figures PATENTED JUU 8 m2 SHEET 1 [IF 2 MES kwm PATENTEB Juu8 I972 3,677,134

sum 2 OF 2 GUNNERY CONTROL DEVICE FOR TURRET-MOUNTED FIREARM FIELD OF THE INVENTION This invention relates to systems for inserting corrections into gun control devices.

BACKGROUND To insure a high probability of hitting a moving target on the first shot requires the insertion of corrections which are dependent on the kinematic characteristics of the target, namely: its distance and rate of displacement with respect to the gun. In fact, to register a hit on a target maneuvering at distance D, at a velocity V perpendicular to the line of sight, requires firing ahead of such target at an angular displacement equal to the product VT/D where T is the time of flight of the projectile corresponding to distance D, and V/D=Q is the apparent angular velocity seen from the turret.

SUMMARY OF THE INVENTION The device provided in accordance with the present invention permits the measurement of Q by means of a suitable aiming system and then, given the value of T, two equal and opposite orders of firing correction can be elaborated and each of these corrections introduced respectively into the gun aiming and laying systems so that the line of sight, after correction, stays aligned on the target. The only constraint on the gunlayer is that prior to the automatic insertion of those corrections, he must keep his line of sight on the target.

The improvements of the invention with respect to existing devices are of two kinds:

the measurement of velocity is far more accurate and less a matter of chance thus insuring a better value of the correction instructions, particularly at long distances;

the automatic insertion of firing corrections into the weapon-laying system without intervention by the fire commander, that is to say, without change in his laying orders.

BRIEF DESCRIPTION OF DRAWING FIG. I is a schematic diagram of a correction system provided in accordance with the invention; and

FIG. 2 is a view of a portion of the apparatus of FIG. 1 partially broken away.

DETAILED DESCRIPTION In the drawing, manual laying drives 1 are mechanically linkedto the slide of a potentiometer 2. The voltage obtained between the slide of that potentiometer and ground, proportional to the forced elevation, constitutes the order of reference of a positional damping arrangement 3 of the governor shaft of a variable speed gear 4. This shaft in its movement operates the slide of potentiometer 5 known as the shaft position retrace. The voltage delivered by this potentiometer is compared with the frame of reference in a differential amplifier 6 driving the servomotor 7.

The variable speed ball gear comprises three parts:

a disk 8 driven at constant speed by a synchronous motor 9;

a roller 10 driving the variable speed output shaft 10' and lying in a plane parallel with that of the disk;

a disk-to-roller connection through balls mounted in a flynut 11. The balls move along the disk following a diameter parallel to a generating line of the roller. The roller speed is proportional to the position of the balls on the disk. This is equal to zero when the balls are at the center of the disk and maximum when they are at the periphery. This way and because of the properties of the ball speed change mechanism 4, an extremely uniform delivery speed is obtained and indicated accurately by potentiometer 5 which duplicates the position of the balls.

The delivery shaft 10' of roller 10 of the speed change drives, at forced" speed (I, the rotor of an angular position interceptor 12, whose stator is mechanically connected to the turret by the reduction gearbox 13. An angular shift between the interceptor rotor and stator produces an electric signal proportional to such shift which constitutes the damping error signal for the position of the turret at the sighting order Amplifier l4 amplifies the control error signal and governs the hydraulic output of a servo valve 15. Thisservo valve feeds the hydraulic engine 16 which drives turret 17 by means of reduction gear 13 in the direction tending to cancel out the angular displacement.

The measurement of target speed derives directly from the sighting device. In order to learn the target speed of progress, the gunlayer chases it. To this order of sighting, there is only one corresponding position of the balls on the disk, of which position the electrical value is known through potentiometer 5. This electrical equivalent is also that of the rate of progress. The basis of the detennination of the tachometric correction is as follows:

The gunlayer chasing the target with his range finder integrally mounted on the gun, has the turret rotating at speed (I. The electronic multiplier works out the product of Q by T where Q is an electric voltage feeding a potentiometer 18, in which the position of the contact slide is a function of T. The result of the product is an electric voltage representing the value a Q T of the firing correction angle. This value is brought into the aiming system where it constitutes the damping entry order 19 for the vertical cross hair 20 which then moves by an. amount equivalent to a. This reticle displacement is joined to that of the slide of potentiometer 21 which works out the correction order which is added to the aiming command in amplifier 14 of servo valve 15 so that the instantaneous movement of the turret ahead of the target is equal to angle a.

For the gunlayer, at the end of correction, the target is displaced in the field of his sight gage, but the aiming marks being correctly offset, the line of sight remains fixed on the same point of the target as before the correction. This automatic insertion on the gunlayer order and the matching of the turret and reticle displacements requires no change in the aiming orders, since after the correction, the gunlayer continues to chase the target and can fire in the best time-limit for such intervention.

In the above, there is disclosed a system for the automatic insertion of firing corrections for gun control devices. The system comprises a sighting means whose bearing is mechanically secured to remain parallel with the firing axis. The arrangement consists of a means capable of shifting the axis of sight or the sight line marks or reticle in proportion to the corrections and associated with a positional shift of the line of fire, of which the initial command is made up of the sum of the laying or bearing entries and an amount whose value is equal and opposite to the value of the corrections so that when those corrections have been inserted, the firing line moves by an amount equal and opposite to the line of sight which thus stays fixed on target.

In the said system, the correction inserted is the firing correction on a moving target. The said firing correction on moving target depends on the following:

a. first, a method capable of generating a quantity of which at any instant the value (I) and the value of the derivative 0 are known, the quantity 4: constituting the aiming order;

b. a second method to generate an amount proportional to the product of the derivative 9. by an amount proportional to the time of flight T of the projectile and to shift the axis of sight or the sight line marks by an angle a equal to the quantity represented by that product so that the line of sight shifts inversely to the direction of the target;

c. a third method to hold down the position of the line of fire to a required position, whose initial command is made up of the sum of the aiming orders and correction orders.

The quantity .0 mentioned above is in proportion to the speed of the delivery shaft of an electromechanical pilot system and variable speed generator, the aiming order being proportional to the angular position of the said delivery shaft. The quantity is an electric voltage, the quantity 4: being ascertained after that voltage has traveled into an integrating amplifier. The delivery shaft of said electromechanical pilot variable speed generating system is that of a variable reducer having a ratio K associated with a control of its adjustmentdrive position.

The said adjustment-drive position control comprises: a motor-generator driving the variable reducer feedshaft at speed K; an amplifier controlling the voltage of the motor windings, starting from the voltage difference between the reference voltage proportional to KS) and the voltage of the tachogenerator associated with the motor.

The electromechanical pilot variable speed generating system mentioned above has an output shaft which is that of a mechanical variable speed reducing gear whose primary shaft is driven at constant speed and of which the mechanical adjustment of the reduction ratio is effected by positional control of the adjustment drive.

The aforesaid means of controlling the position of the axis of fire comprises: an angular drift detector made up of a stator connected to the turret by gearing and a rotor integral with the output shaft of the electromechanical pilot variable speed generating system; an integrating amplifier receiving the electrical signal resulting from the shift between the detector stator and rotor for a set aiming angle and the electrical signal corresponding to the firing correction angle; and a motor driving the turret by means of a reducing gear in a direction leading to cancellation of the control signals.

The integrating amplifier mentioned above as relating to control of the firing line or axis, comprises: an angular position detector whose stator is stationary and whose rotor is connected to the turret by gearing, delivering a voltage equal to the electrical value of the effective aiming angle (p, of the turret; a differential amplifier to compare the electrical value of the required aiming angle 11; to the value of the effective aiming angle and a motor driven by the error signal resulting from a comparison between 4; and (1: and driving the turret through a reducing gear in a direction leading to cancellation of the error signal.

The angular drift detector is made up of a synchro transmitter generating the required aiming value 4), with a rotor integral with the output shaft of the aforesaid electromechanical pilot variable speed generating system; a differential synchro which allows addition to the value 41 of the value of the angle a for firing correction introduced by the shift of said angle a of the rotor in respect to the stator; and a synchro receiver whose stator is stationary and whose rotor which is connected to the turret by gearing generates a voltage of amplitude equal to the electrical value of the angular difference between the position of the turret and the required position after correction.

The angular drift detector, in which the synchro transmitter is a resistance or induction potentiometer, whose stator is integral with the turret and whose rotor is driven by the shaft of the electromechanical pilot variable speed generator system, delivers a voltage equal to the electrical value of the angular difference between the turret position and the position of the output shaft of the said electromechanical pilot system.

The motor mentioned above is a hydraulic motor driving the turret, its output being controlled by one or more servo valves electrically driven on the basis of the sum of aiming orders and fire correction orders.

The quantity 9 mentioned above is a frequency, the quantity dz being a number N of pulses, each pulse representing an increment in aiming angle. The subjecting of the firing axis to the aiming and correction instructions is effected by the aid of a picking motor. At each pulse, the motor shifts the gun axis by one angle increment. A numerical totalizer sends the picking motor the sum of the N pulses corresponding to the aiming instruction and of those corresponding to the correction instruction.

A second picking motor receiving only the pulses equivalent to the correction instruction shifts the sightline marks by an amount equal and opposite to the angular displacement of the firing axis ahead of the target.

The working-out of the correction mentioned above is obtained in the said second method by a multiplier made up of a potentiometer fed by an electric voltage proportional to speed .0. of the turret and the position of whose slide is controlled at value T of the projectile time of flight. The voltage indicated on the slide is proportional to the value of the angle a 07 and constitutes the correction instruction for shifting of the line of sight and backing-in of the axis of fire ahead of the target.

The working-out of the correction mentioned above is obtained exclusively by electrical multiplication of the values 0 and T given in the form of analog or numerical electrical magnitudes.

A shot at a moving target can be carried out in two phases:

First phase: The marksman follows the designated target by action on the handles 1. Since the viewing device is gimballed to the gun, the pursuit of the target consists of permanently aligning the vertical hairline or network on that target. During this phase, the vertical hairline remains in the center of the optical field of the viewing device, the telemetry is operative and there are provided the two perimeters O and T f (D) for deriving instantly and continuously the product a (IT.

Second phase: The marksman introduces the correction at by closing the switch 22. At this moment, he perceives in the viewing device the simultaneous displacement of the target and the vertical hairline in the same direction. The target is displaced due to shifting of the gun and the viewing device by a quantity or leading the target and the hairline is displaced by a same quantity in the opposite direction to the target. At the end of correction, the vertical nairline is still on target but the gun is pointing to the future target position. In accordance with this principle, the correction or shift of the gun occurs without any need for modifying the position of the handles 1.

What is claimed is:

1. Apparatus comprising a gun having a firing axis, a rotatable turret, means for supporting the gun, laying means for controlling the gun, sighting means associated with the gun to move therewith, said sighting means having a line of sight, correction means to determine position corrections for the gun and to displace the gun in accordance with said corrections to shift said firing axis and line of sight so that the line of sight can remain fixed on a target when directed at the target by an operator, said turret means including a turret, a source of power for rotating the turret, a reduction gear means coupling said source to said turret, and an angular position interceptor including a rotor and stator, the stator being coupled by said gear means to said turret whereby the relationship of the rotor relative to the stator indicates the position of the turret.

2. Apparatus as claimed in claim 1 comprising a variable speed gear to rotate said rotor and control means to control said variable speed means in response to said laying means.

3. Apparatus as claimed in claim 2 wherein said variable speed gear includes a disk, a motor rotating said disk, a roller parallel to said disk and rotatable means between the roller and disk and adjustable diametrally along the latter and longitudinally along the roller, said roller being coupled to said rotor.

4. Apparatus as claimed in claim 3 wherein said control means is coupled to and adjusts the position of said rotatable means, said correction means including a potentiometer coupled to said laying means and a servo motor coupled to said potentiometer and operating said control means.

5. Apparatus as claimed in claim 4 comprising a second potentiometer indicating the position of said rotatable means, a third potentiometer coupled to said potentiometer to receive a signal therefrom representing S). wherein n. is the angular velocity of a target perpendicular to the line of sight, and being further adapted to receive a signal representing T wherein T is the time of flight of a projectile to said target, said axis and line of sight, said source of power including a control valve and an operating means coupled to and operating said control valve and in turn coupled to and operated by said rotor and fourth potentiometer.

UNITEDSTATES PATENT UFHQE (1E TEHCATE 0F Q6 EQ'HQN Patent No. 3,677,134 Dated July 1.8, 1972 Inventor(s) Jacques Paul Robert Maxims et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

0n the cover sheet [72] the inventor's name "Jacques Paul Robert Maximi" should appear Jacques Paul Robert Maxime Signed and sealed this 12th day of December 1972'.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attescing Officer Commissioner of Patents FORM PO-1050 (10-69) *1 us. GOVERNMENT PRINTING OFFICE: 1969 o-36s-3:14,

UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION I Patent No. 3,677,134 Dated 'July 18, 1972 Inventor(s) Jacques Paul Robert Maxime et 31 It is certified that error appearsin the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below: 7

-.On the cover sheet [72] the inventor: name "Jacques Paul Robert Maximi" should appear Jacques" Paul Robert Maximo d Signed and sealed this 12th day of December 1972'.

(S Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents USCOMM-DC 6087 6-P6Q FORM PO-1050 (10-69) v: u.s. GOVERNMENT PRINTING OFFICE: 1969 o-ase-au.

Claims

5. Apparatus as claimed in claim 4 comprising a second potentiometer indicating the position of said rotatable means, a third potentiometer coupled to said potentiometer to receive a signal therefrom representing Omega wherein Omega is the angular velocity of a target perpendicular to the line of sight, and being further adapted to receive a signal representing T wherein T is the time of flight of a projectile to said target, said third potentiometer being coupled to and controlling said adjustment means.

6. Apparatus as claimed in claim 5 wherein said adjustment means includes a fourth potentiometer coupled to said third potentiometer and indicating the relative shifting of the firing axis and line of sight, said source of power including a control valve and an operating means coupled to and operating said control valve and in turn coupled to and operated by said rotor and fourth potentiometer.