Reduced noise estimator

Patent metadata

Field	Value
Publication number	US-11698244-B2
Application number	US-201917263941-A
Country	US
Kind code	B2
Filing date	Aug 30, 2019
Priority date	Aug 31, 2018
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A system and method to aid in guidance, navigation and control of a guided projectile including a precision guidance munition assembly is provided. The system and method obtain raw position data during flight of the guided projectile, the raw position data including a plurality of position data points from the guiding sensor for determining positions of the guided projectile, establish a window including a portion of the plurality of position data points, smooth the portion of the plurality of position data points in the window, and determine a reduced noise position estimate of the guided projectile, based, at least in part, on the smoothed portion of the plurality of position data points in the window. The system and method may determine a velocity estimate of the guided projectile and predict an impact point of the guided projectile relative to a target.

First claim

The invention claimed is:

1. A precision guidance munition assembly for a guided projectile, comprising:
a canard assembly including at least one canard coupled to the precision guidance munition assembly, wherein the at least one canard is moveable;
at least one guiding sensor coupled to the precision guidance munition assembly; and
at least one non-transitory computer-readable storage medium carried by the precision guidance munition assembly having a set of instructions encoded thereon that when executed by at least one processor operates to aid in guidance, navigation and control of the guided projectile, wherein the set of instructions comprise:
obtain a plurality of raw position data during the flight of the guided projectile, including a plurality of position data points from the guiding sensor for determining positions of the guided projectile;
establish a window including a portion from the plurality of position data points;
smooth the portion from the plurality of position data points in the window, utilizing all position data points within the window; and
determine a reduced noise position estimate of the guided projectile, based, at least in part, on the smoothed portion of the plurality of position data points in the window.

2. The precision guidance munition assembly of claim 1 , wherein the guiding sensor is at least one of a global positioning system (GPS), laser guided sensor, electro-optical sensor, imaging sensor, inertial navigation system (INS), and inertial measurement unit (IMU).

3. The precision guidance munition assembly of claim 1 , wherein the set of instructions include:
smooth the portion from the plurality of position data points by utilizing a curve fit representing an expected trajectory shape of the guided projectile.

4. The precision guidance munition assembly of claim 3 , wherein the curve fit is a quadratic fit.

5. The precision guidance munition assembly of claim 1 , wherein the portion of the plurality of position data points includes:
a first position data point representing a first position of the guided projectile at a first time; and
a subsequent position data point representing a second position of the guided projectile at a second time; and
a first reduced noise position estimate representing an estimated position of the guided projectile at the second time.

6. The precision guidance munition assembly of claim 1 , wherein the set of instructions further comprise:
utilize at least one projectile dynamics model to predict a future position of the guided projectile at a future time.

7. The precision guidance munition assembly of claim 6 , wherein the at least one projectile dynamics model is a three degree-of-freedom model.

8. The precision guidance munition assembly of claim 6 , wherein the set of instructions further comprise:
determine a second reduced noise position estimate of the guided projectile based, at least in part, on a weighted sum of the reduced noise position estimate and the predicted future position of the guided projectile.

9. The precision guidance munition assembly of claim 8 , wherein the set of instructions further comprise:
determine a first velocity estimate of the guided projectile.

10. The precision guidance munition assembly of claim 9 , wherein the first velocity estimate of the guided projectile is based, at least in part, on the first reduced noise position estimate of the guided projectile.

11. The precision guidance munition assembly of claim 9 , wherein the set of instructions further comprise:
predict a future velocity estimate of the guided projectile at a second future time using the at least one projectile dynamics model.

12. The precision guidance munition assembly of claim 11 , wherein the at least one projectile dynamics model is a three degree-of-freedom model.

13. The precision guidance munition assembly of claim 11 , wherein the set of instructions further comprise:
determine a second velocity estimate of the guided projectile based, at least in part, on a weighted sum of the first velocity estimate and the predicted future velocity estimate of the guided projectile.

14. The precision guidance munition assembly of claim 1 , wherein the set of instructions further comprise:
predict an impact point of the guided projectile relative to a target.

15. The precision guidance munition assembly of claim 14 , wherein the impact point of the guided projectile is predicted by utilizing the at least one projectile dynamics model.

16. The precision guidance munition assembly of claim 14 , wherein the set of instructions further comprise:
determine whether the guided projectile will miss the target; and
command the guided projectile to move the at least one canard accordingly.

17. A method, comprising:
providing a precision guidance munition assembly configured to be assembled as a guided projectile and launched towards a target;
obtaining a plurality of raw position data during flight of the guided projectile, including a plurality of position data points from a guiding sensor for determining positions of the guided projectile;
establishing a window including a portion of the plurality of position data points;
smoothing the portion of the plurality of position data points in the window, utilizing all position data points within the window; and
determining a reduced noise position estimate of the guided projectile based, at least in part, on the smoothed portion of the plurality of position data points in the window.

18. The method of claim 17 , further comprising:
predicting a future reduced noise position estimate of the guided projectile based, at least in part, on a weighted sum of the reduced noise position estimate and a predicted position of the guided projectile.

19. The method of claim 17 , further comprising:
predicting an impact point of the guided projectile relative to the target;
determining whether the guided projectile will miss the target; and
directing the guided projectile to the target by moving the at least one canard.

20. A computer program product including one or more non-transitory machine-readable mediums having instructions encoded thereon that, when executed by one or more processors, result in a plurality of operations for guiding a projectile, the operations comprising:
obtaining a plurality of raw position data during a flight of the projectile, including a plurality of position data points from at least one guiding sensor for determining positions of the projectile;
establishing a window including a portion of the plurality of position data points;
smoothing the portion of the plurality of position data points in the window, utilizing all the position data points in the window, utilizing a curve fit representing an expected trajectory shape of the guided projectile to produce a smoothed portion;
determining a reduced noise position estimate of the guided projectile, based, at least in part, on the smoothed portion of the plurality of position data points in the window;
predicting an impact point of the guided projectile relative to the target;
determining whether the guided projectile will miss the target; and
directing the guided projectile to the target by moving the at least one canard.

Assignees

• Bae Sys Inf & Elect Sys Integ

Inventors

• Zemany Paul D
• Chrobak Matthew F

Classifications

• F41G7/001 Primary

  Devices or systems for testing or checking · CPC title

• F42B10/64

  of fins · CPC title

• F41G7/346 Primary

  using global navigation satellite systems, e.g. GPS, GALILEO, GLONASS · CPC title

• G05D1/107

  specially adapted for missiles · CPC title

• F41G7/008

  Combinations of different guidance systems · CPC title