Method and system for establishing a correct lead when firing at a moving target

Claim 2

In a weapon and sight system including an angularly rotatable weapon and sighting instrument with an angularly rotatable line of sight the method of providing a correct lead angle between the direction of fire of the weapon and the line of sight of the sighting instrument when firing a projectile from the weapon against a moving target comprising the steps of: moving the line of sight of the sighting instrument so as to keep it pointing at the moving target; rotating said weapon so as to move the direction of fire thereof uniformly with the movement of the line of sight of the sighting instrument without any relative angular velocity between the direction of fire and the line of sight; continuously measuring the angular velocity of the line of sight; integrating the angular velocity of the line of sight over a predetermined limited time interval; at the end of said time interval substantially momentarily deflecting the direction of fire of said weapon and the line of sight of said sighting instrument from each other by an angle proportional to the integrated value of the angular velocity of the line of sight in such relative direction that the direction of fire of the weapon will lead the line of sight of the sighting instrument as seen in the direction of the angular movement of the target; and subsequently continuing to move the direction of fire of said weapon uniformly with the movement of the line of sight of the sighting instrument until a projectile is fired against the target.

Claim 3

The method as claimed in claim 1, wherein said limited time interval is selected to be equal to the product of a constant and the range to the moving target, and at the end of the limited time interval the line of sight of the sighting instrument and the direction of fire of the weapon are deflected from each other by an angle proportional to the integrated value of the angular velocity of the line of sight divided by the mean velocity of a projectile fired at the target.

Claim 4

The method as claimed in claim 1, compRising the additional step at the end of said limited time interval of momentarily deflecting the line of sight of said sighting instrument and the direction of fire of said weapon from each other not only by said angle proportional to the integrated value of the angular velocity of the line of sight but also by a computed superelevation angle and computed correction angles for wind forces acting upon a projectile fired at the target and for the rotation of the projectile.

Claim 5

A weapon and sight system comprising: an angularly rotatable weapon; a sighting instrument with an angularly rotatable line of sight, said weapon and said sighting instrument being coupled to each other so that the line of sight of the sighting instrument and the direction of fire of the weapon normally move uniformly without any relative angular velocity; first servo-drive means for angularly rotating the line of sight of said sighting instrument; manually operable means for generating a manually variable control signal for said first servodrive means for tracking a moving target with the line of sight of the sighting instrument; and lead angle computing means for providing a correct lead angle between the direction of fire of the weapon and the line of sight of the sighting instrument when firing a projectile at the target being tracked, said lead angle computing means comprising means for measuring the angular velocity of the line of sight of the sighting instrument and producing a signal proportional thereto, timing means for determining a time interval proportional to the range to the target being tracked, means for initiating the operation of said timing means at a selected instant, signal integrating means, second servodrive means for angularly deflecting the direction of fire of said weapon and the line of sight of said sighting instrument from each other by an angle proportional to a control signal supplied to said second servo-drive means, first switching means responsive to the operation of said timing means to apply said signal proportional to the angular velocity of the line of sight of the sighting instrument to the input of said signal integrating means during said time interval, and second switching means responsive to the operation of said timing means to apply at the end of said time interval the output signal of said signal integrating means as a control signal to said second servo-drive means.

Claim 6

A weapon and sight system comprising: an angularly rotatable weapon; a sighting instrument with an angularly rotatable line of sight, said weapon and said sighting instrument being coupled to each other so that the line of sight of the sighting instrument and the direction of fire of the weapon normally move uniformly without any relative angular velocity; first servo-drive means for angularly rotating the line of sight of said sighting instrument; manually operable means for generating a manually variable control signal for said first servodrive means for tracking a moving target with the line of sight of the sighting instrument; and lead angle computing means for providing a correct lead angle between the direction of fire of the weapon and the line of sight of the sighting instrument when firing a projectile at the target being tracked, said lead angle computing means comprising means for measuring the angular velocity of the line of sight of the sighting instrument and producing a signal proportional thereto, timing means for determining a time interval proportional to the range to the target being tracked, means for initiating the operation of said timing means at a selected instant, signal integrating means, second servodrive means for angularly deflecting the direction of fire of said weapon and the line of sight of said sighting instrument from each other by an angle proportional to a control signal supplied to said second servo-drive means, first switching means responsive to the operation of said timing means to apply said signal proportional to the angular velocity of the line of sight of the sighting instrument to the input of said signal integrating means during said time interval, and second switching means responsive to the operation of said timing means to apply at the end of said time interval the output signal of said signal integrating means as a control signal to said second servo-drive means.

Claim 7

The weapon and sight system as claimed in claim 4, wherein said timing means is adapted to determine a time interval equal to the product of a constant and the range to the target being tracked, said second servo-drive means including rotating servomotor means and signal generating means coupled to said servomotor means for generating a negative feed-back signal for said servomotor means proportional to the product of the angle of rotation of said servomotor means and a reference signal supplied to said signal generating means, and wherein said lead angle computing means comprise means for computing the mean velocity for a projectile fired at the target being tracked and producing a signal proportional to said mean velocity, said signal being supplied to said signal generating means as said reference signal.

Claim 8

A weapon and sight system as claimed in claim 5, wherein said first servo-drive means is adapted to angularly rotate said weapon, said sighting instrument is mounted on said weapon so as to participate in its movements, and said servomotor means of said second servo-drive means is adapted to angularly rotate the line of sight of the sighting instrument relative to the direction of fire of the weapon.

Claim 9

A weapon and sight system as claimed in claim 6, comprising second signal generating means coupled to said servomotor means of said second servo-drive means for generating a signal representing the rotation of said servomotor means, said signal being applied to said first servo-drive means for rotating said weapon As an additional control signal assisting said manually variable control signal.