초록 ▼

A missile guidance system is configured to estimate a time to go, the time to go comprising an amount of time until a missile would reach a closest point of approach to a target. The guidance system is also configured to estimate a zero-effort miss distance along a zero-effort miss vector, the zero-

A missile guidance system is configured to estimate a time to go, the time to go comprising an amount of time until a missile would reach a closest point of approach to a target. The guidance system is also configured to estimate a zero-effort miss distance along a zero-effort miss vector, the zero-effort miss distance comprising a distance by which the missile would miss the target if the missile performs no future maneuvers. The guidance system is also configured to determine a tolerance for the zero-effort miss distance, the tolerance being a function of the time to go. The guidance system is further configured to modify a course of the missile by adjusting an expenditure of propellant such that the estimated zero-effort miss distance in excess of the tolerance is removed from future consideration.

대표청구항 ▼

1. A missile guidance system comprising: a computer processor;a control system coupled to the computer processor; anda propellant storage container coupled to the control system;wherein the computer processor is operable to:(a) estimate a time to go, the time to go comprising an amount of time until

1. A missile guidance system comprising: a computer processor;a control system coupled to the computer processor; anda propellant storage container coupled to the control system;wherein the computer processor is operable to:(a) estimate a time to go, the time to go comprising an amount of time until a missile would reach a closest point of approach to a target;(b) estimate a zero-effort miss distance along a zero-effort miss vector, the zero-effort miss distance comprising a distance by which the missile would miss the target if the missile performs no future maneuvers;(c) determine a tolerance for the zero-effort miss distance, the tolerance being a function of the time to go; and(d) modify a course of the missile by adjusting an expenditure of propellant such that the zero-effort miss distance in excess of the tolerance is removed from future consideration. 2. The missile guidance system of claim 1, wherein the system is configured to repeat steps (a) through (d) until the missile intercepts the target. 3. The missile guidance system of claim 1, wherein the system is configured to execute steps (a) through (d) during a midcourse time period of a flight of the missile, thereby preparing the missile for a terminal phase of the flight of the missile; and thereafter ceasing execution of steps (a) through (d), thereby handing off control of the missile to the terminal phase. 4. The missile guidance system of claim 1, wherein tolerance values as a function of the time to go are generated prior to a flight of the missile, wherein the tolerance values are determined by a minimization of an integral of an expectation value of an absolute value of an acceleration of the missile during a midcourse phase and a terminal guidance phase of the missile. 5. The missile guidance system of claim 4, wherein the determination of the tolerance values is a function of a rate of change over time in an uncertainty in the zero-effort miss distance, assuming no evasive maneuver by the target. 6. The missile guidance system of claim 1, wherein the missile is capable of maneuver in a plane orthogonal to a line of sight from the missile to the target. 7. The missile guidance system of claim 6, wherein the system is configured to cause the missile to roll such that a single thruster points along the zero-effort miss vector, and to execute steps (a)-(d) for the single thruster. 8. The missile guidance system of claim 6, wherein the system is configured to apply steps (a)-(d) independently along two orthogonal axes in a maneuver plane. 9. The missile guidance system of claim 1, wherein the adjustment of an expenditure of a propellant is executed when the zero-effort miss distance exceeds the tolerance, and the expenditure of propellant is executed to cause a divert such that the zero-effort miss distance becomes equal to or less than the tolerance. 10. The missile guidance system of claim 1, wherein the system is configured to expend no propellant when the zero-effort miss distance is less than the tolerance. 11. A non-transitory computer readable storage medium comprising instructions that when executed by a processor execute a process comprising: (a) estimating a time to go, the time to go comprising an amount of time until a missile would reach a closest point of approach to a target;(b) estimating a zero-effort miss distance along a zero-effort miss vector, the zero-effort miss distance comprising a distance by which the missile would miss the target if the missile performs no future maneuvers;(c) determining a tolerance for the zero-effort miss distance, the tolerance being a function of the time to go; and(d) modifying a course of the missile by adjusting an expenditure of propellant such that the zero-effort miss distance in excess of the tolerance is removed from future consideration. 12. The non-transitory computer readable medium of claim 11, further comprising instructions configured to repeat steps (a) through (d) until the missile intercepts the target. 13. The non-transitory computer readable medium of claim 11, further comprising instructions configured to execute steps (a) through (d) during a midcourse time period of a flight of the missile, thereby preparing the missile for a terminal phase of the flight of the missile; and thereafter ceasing execution of steps (a) through (d), thereby handing off control of the missile to the terminal phase. 14. The non-transitory computer readable medium of claim 11, wherein tolerance values as a function of the time to go are generated prior to a flight of the missile, and wherein the tolerance values are determined by a minimization of an integral of an expectation value of an absolute value of an acceleration of the missile during a midcourse phase and a terminal guidance phase of the missile. 15. The non-transitory computer readable medium of claim 14, wherein the determination of the tolerance values is a function of a rate of change over time in an uncertainty in the zero-effort miss distance, assuming no evasive maneuver by the target. 16. The non-transitory computer readable medium of claim 11, further comprising instructions configured to cause the missile to maneuver in a plane orthogonal to a line of sight from the missile to the target. 17. The non-transitory computer readable medium of claim 16, further comprising instructions configured to cause the missile to roll such that a single thruster points along the zero-effort miss vector, and to execute steps (a)-(d) for the single thruster. 18. The non-transitory computer readable medium of claim 16, further comprising instructions configured to apply steps (a)-(d) independently along two orthogonal axes in a maneuver plane. 19. The non-transitory computer readable medium of claim 11, wherein the adjustment of an expenditure of a propellant is executed when the zero-effort miss distance exceeds the tolerance, and the expenditure of propellant is executed to cause a divert such that the zero-effort miss distance becomes equal to or less than the tolerance. 20. The non-transitory computer readable medium of claim 11, further comprising instructions configured to expend no propellant when the zero-effort miss distance is less than the tolerance. 21. A method for missile guidance comprising: (a) estimating a time to go, the time to go comprising an amount of time until the missile would reach a closest point of approach to a target;(b) estimating a zero-effort miss distance along a zero-effort miss vector, the zero-effort miss distance comprising a distance by which the missile would miss the target if the missile performs no future maneuvers;(c) determining a tolerance for the zero-effort miss distance, the tolerance being a function of the time to go; and(d) modifying a course of the missile by adjusting an expenditure of propellant such that the zero-effort miss distance in excess of the tolerance is removed from future consideration.