초록 ▼

A method is provided for guiding a mortar projectile fired longitudinally from a launcher along a ballistic trajectory. The method includes providing a first inertial navigation system (INS), a laser emitter and optical sensor on the launcher, providing a second INS and a laser reflector on the proj

A method is provided for guiding a mortar projectile fired longitudinally from a launcher along a ballistic trajectory. The method includes providing a first inertial navigation system (INS), a laser emitter and optical sensor on the launcher, providing a second INS and a laser reflector on the projectile, and presetting the second INS to an initial reference position prior to firing the projectile. Subsequent to launch, the method further includes emitting a longitudinally directed laser beam from the emitter to the reflector; receiving the reflected signal to the optical sensor; establishing a position and velocity of the projectile based on the reflected signal; transmitting a correction signal to the projectile from the launcher; resetting the second INS at a position prior to reaching maximum altitude; and guiding the projectile along the trajectory by adjusting control fin orientation.

대표청구항 ▼

1. A method for guiding along a ballistic trajectory a mortar projectile fired longitudinally towards a target from a launcher through a muzzle, said launcher equipped with an inertial navigation system (INS), said method comprising: providing a mortar INS for the projectile loaded in the launcher s

1. A method for guiding along a ballistic trajectory a mortar projectile fired longitudinally towards a target from a launcher through a muzzle, said launcher equipped with an inertial navigation system (INS), said method comprising: providing a mortar INS for the projectile loaded in the launcher synchronized with the INS;providing a laser emitter and an optical sensor on the launcher directed longitudinally towards the muzzle;providing a laser reflector on an aft-facing surface of the projectile;presetting said mortar INS to an initial reference ground position prior to firing the projectile;emitting a longitudinally directed laser beam from said emitter to said reflector less than one millisecond subsequent to firing the projectile, said reflector reflecting said beam as a reflected signal;receiving said reflected signal to said optical sensor;determining a first in-flight state of ground position, altitude and velocity of the projectile by the INS on the launcher based on said reflected signal;transmitting a correction signal from the launcher to a receiver on the projectile, said correction signal providing said first in-flight state relative to the launcher;resetting said mortar INS at a second in-flight state, extrapolated from said first in-flight state, prior to reaching maximum altitude based on said correction signal; andguiding the projectile to adjust its control fin orientation to thereby engage the target. 2. The method according to claim 1, wherein said reflector exhibits a reflection efficiency that varies monotonically with an angle between said beam and a centerline of said reflector. 3. The method according to claim 1, wherein said second in-flight state includes ground position, altitude and velocity. 4. The method according to claim 1, wherein said emitter fires said beam in a series of pulses. 5. The method according to claim 1, wherein adjusting orientation of said fins minimizes yaw and pitch moments of the projectile. 6. The method according to claim 1, wherein said guiding operation further includes adjusting control fin position of the projectile to maximize amplitude of said reflected signal. 7. The method according to claim 6, wherein said control fin position of the projectile is set to maximize amplitude of said reflected signal. 8. The method according to claim 1, wherein said guiding operation further includes: measuring a first distance between the launcher and the projectile,measuring a second distance between the launcher and the projectile at a time interval of less than one millisecond from said first distance, anddetermining a velocity of the projectile by differencing said first and second distances. 9. The method according to claim 1, wherein said guiding operation further includes: determining a first frequency of said reflected signal at a first time,determining a second frequency of said reflected signal at a second time at a time interval of less than one millisecond from said first frequency, anddetermining a velocity of the projectile by determining a Doppler shift of said reflected signal. 10. The method according to claim 1, wherein said transmitting said correction signal includes position of the mortar and time of measurement. 11. A system for guiding a projectile fired longitudinally from a launcher along a ballistic trajectory towards a target, said projectile having control surfaces, said system comprising: a first inertial navigation system (INS) for the launcher;a second INS for the projectile loaded in the launcher, said second INS being set to an initial reference position prior to being fired from the projectile and synchronized with said first INS;a laser emitter with an optical sensor on the launcher directed longitudinally, such that said emitter emits a longitudinally directed laser beam to said reflector less than one millisecond subsequent to firing the projectile;a laser reflector on an aft-facing surface of the projectile to reflect said laser beam as a reflected signal to said optical sensor; anda signal transmitter on said launcher for sending a correction signal to a receiver on the projectile, said correction signal providing an in-flight state of ground position, altitude and velocity of the projectile based on said reflected signal, whereinsaid optical sensor receives said reflected signal,said first INS establishes a position and velocity of the projectile based on said reflected signal,said second INS resets a position of said projectile prior to reaching maximum altitude based on said correction signal; andthe control surfaces adjust orientations responsive to said second INS for adjusting the trajectory of the projectile to engage the target. 12. The system according to claim 11, wherein said correction signal includes ground position, altitude, and velocity of the projectile and time of measurement. 13. The system according to claim 11, wherein said reflector exhibits a reflection efficiency that varies monotonically with an angle between said beam and a centerline of said reflector. 14. The system according to claim 11, wherein said second in-flight state includes ground position, altitude and velocity. 15. The system according to claim 11, wherein said emitter fires said beam in a series of pulses. 16. The system according to claim 11, wherein said control surfaces of the projectile are oriented to minimize yaw and pitch moments of the projectile. 17. The system according to claim 11, wherein said control surfaces of the projectile are oriented to maximize amplitude of said reflected signal.