Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus clears the barrel and/or prevents water from entering the barrel based on pressure variations.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises an adapter that attaches to the barrel and includes a physical adaptation that is capable of sealing the barrel. In some embodiments, the physical adaptation is actuated to un-seal the barrel via combustion gases from firing of a round.

Abstract: A projectile system includes an enclosure, first and second propellants, and first and second projectiles. The first and second propellants are disposed within the enclosure. The first projectile is disposed within the enclosure between the first propellant and a first end of the enclosure, and is operable to exit the enclosure via the first end in response to detonation of the first charge. The second projectile is disposed within the enclosure between the second propellant and a second end of the enclosure, and is operable to exit the enclosure via the second end in response to the detonation of the second propellant.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a turbine that is disposed at the outlet of the muzzle of the gun. The turbine draws in water and, in various embodiments, either (a) vaporizes it, forming a vapor barrier along the spin axis that keeps water out of the barrel, (b) expels it radially, thereby re-directing it so that it does not enter the barrel, or (c) generates water jets that prevent water from entering the barrel.

Abstract: A mechanism for empirically deriving the values of the damping ratio and frequency of the mechanism driven by a servo-controlled control system is disclosed. In accordance with the illustrative embodiment, the values of the damping ratio and frequency are continually re-generated based on empirical data derived from sensor feedback of the maximum-amplitude switch and the linear second-order servo. Because the values of the damping ratio and frequency are generated from empirical data, it is not necessary that they be known, and because the values of the damping ratio and frequency are continually re-generated, variances in their values are continually noticed and compensated for.

Abstract: A technique for controlling the pitch of a supercavitating projectile is disclosed. For example, the illustrative embodiment controls the pitch of a supercavitating projectile by shifting its center of gravity. The center of gravity of the projectile is shifted by moving a ferromagnetic mass inside the projectile forward or backward, depending on the desired pitch. In some embodiments of the present invention, the position of the ferromagnetic mass is directed by a controller that has a predetermined trajectory stored in its memory.

Abstract: A method is disclosed for packaging sub-munitions within stacks of same, in a cylindrical payload space, such that the sub-munitions emerge into a circular delta grid pattern when deployed.

Abstract: A method is disclosed for packaging sub-munitions within stacks of same, in a cylindrical payload space, such that the sub-munitions emerge into a circular delta grid pattern when deployed.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a valve that is moved between a sealing and non-sealing state by a valve-actuator. In some embodiments, the valve actuator is driven by gases that result when a round is fired.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a valve that is moved between a sealing and non-sealing state by a valve-actuator. In some embodiments, the valve actuator is driven by gases that result when a round is fired.

Abstract: A mechanism for empirically deriving the values of the damping ratio and frequency of the mechanism driven by a servo-controlled control system is disclosed. In accordance with the illustrative embodiment, the values of the damping ratio and frequency are continually re-generated based on empirical data derived from sensor feedback of the maximum-amplitude switch and the linear second-order servo. Because the values of the damping ratio and frequency are generated from empirical data, it is not necessary that they be known, and because the values of the damping ratio and frequency are continually re-generated, variances in their values are continually noticed and compensated for.

Abstract: A test system that is capable of evaluating the effectiveness of a weapons system designed to defeat an incoming, fast-moving, underwater munition is disclosed. In the illustrative embodiment, an extremely large tubular sheath is inflated underwater. The sheath is maintained at a depth and inclination that is appropriate for an incoming torpedo. An inert projectile is launched or flown inside the sheath at a speed that is consistent with the speed of munition that the weapons system is intended to defeat.

Abstract: A method for operating a supercavitating projectile is disclosed.

Abstract: A method for operating a supercavitating projectile is disclosed.

Abstract: A projectile system includes an enclosure, first and second propellants and first and second projectiles. The first and second propellants are disposed within the enclosure. The first projectile is disposed within the enclosure between the first propellant and a first end of the enclosure, and is operable to exit the enclosure via the first end in response to detonation of the first charge. The second projectile is disposed within the enclosure between the second propellant and a second end of the enclosure, and is operable to exit the enclosure via the second end in response to the detonation of the second propellant.

Abstract: Methods and systems for controlling a servo are provided. One method includes calculating at least a first switching time to change an amplitude of a command signal to a servo, providing a first amplitude to the servo for the first switching time, and switching the amplitude of the command signal to the servo from the first amplitude to a second amplitude at the first switching time. The second amplitude is the command signal amplitude.

Abstract: Apparatuses and methods for switching servos for rapid settling times and nil overshoot without the use of sensors include switching times and the application of varying amplitudes at the switching times to control the servo without the use of sensors.