Granted Patent B1

US 12,736,971 · App. 17/725,268 · Granted Sep 15, 2026

Inventor: Benjamin P. Wood (Bedford, MA)

Assignee: BAE Systems Information and Electronic Systems Integration Inc.

G05D1/106G01S13/935G01S17/933G05D1/104

Abstract

Claims (67)

1 . A computer program product including at least one non-transitory computer readable storage medium having instructions encoded thereon that, when executed by one or more processors, implement a process track an object, the process comprising:

detecting the object;

tracking the object using a first passive sensor on a first platform and obtaining first angular data from tracking the object;

determining a range of the object from the first platform as a closed-form function of time;

deriving a range-rate of the object from the closed-form function of time;

approximating a time-to-go until a collision point between the object and the first platform, wherein approximating the time-to-go is based on a ratio of the range to the range-rate; and

tracking the object using a second passive sensor on a second platform and obtaining second angular data from tracking the object; and

sharing at least one of the first angular data and the second angular data across a communication link between the first platform and the second platform;

wherein determining the range of the object from the first platform as a closed-form function of time is accomplished by triangulating a position of the object based on the first angular data and the second angular data.

2 . The computer program product of claim 1 , further comprising:

generating the range and a range error in response to triangulating the position of the object based on the first angular data and the second angular data; and

providing the range and the range error to a state estimator; and

creating, via the state estimator, a filtered range based on the range and the range error.

3 . The computer program product of claim 2 , wherein creating the filtered range comprises:

curve fitting a filter to a set of polynomial measurements representative of position of the object, wherein performing the curve fitting results in the closed-form function of time.

4 . The computer program product of claim 1 , further comprising:

sharing a message data type representative of a warning track of the object; wherein the sharing of the message data types occurs continuously between the first platform and the second platform for a period of time.

5 . The computer program product of claim 4 , wherein the message data type representative of the warning track of the object includes an indicator of a collision between one of the first platform and the second platform and the object.

6 . The computer program product of claim 5 , further comprising:

determining, via logic at the first platform, whether there is a corresponding warning track of the object located by the second passive sensor on the second platform.

7 . The computer program product of claim 6 , wherein determining whether there is the corresponding warning track is accomplished by determining whether there is inertially consistent similarity in the corresponding track from the second passive sensor and the warning track from the first passive sensor.

8 . The computer program product of claim 7 , further comprising:

matching the first angular data and the second angular data in response to a determination that there is inertially consistent similarity in the corresponding track from the second passive sensor and the warning track from the first passive sensor;

triangulating the position of the object in response to matching the first angular data and the second angular data.

9 . The computer program product of claim 1 , wherein approximating the time-to-go until the collision point between the object and the first platform based comprises:

estimating acceleration or deceleration of the object relative to the first platform.

10 . The computer program product of claim 9 , further comprising:

providing estimated acceleration or deceleration of the object to a state estimator to create a filtered range.

11 . The computer program product of claim 10 , wherein providing estimated acceleration or deceleration of the object to the state estimator occurs subsequent to deriving the range-rate.

12 . The computer program product of claim 1 , further comprising:

providing a signal representative of the time-to-go to a counter measure system.

13 . The computer program product of claim 1 , further comprising:

presuming, based on a priori knowledge from the object having been detected, that the object is moving toward the first platform.

14 . The computer program product of claim 13 , further comprising:

determining a position of the object based on tracking the object using the first passive sensor;

curve fitting a function from noisy measurements from determining the position of the object, wherein curve fitting the function generates a smooth curve that approximates expected behavior of the moving object.

15 . An object ranging method comprising:

tracking, via a first passive sensor on a first platform, an object that is moving;

obtaining first angular data of the object relative to the first platform via the first passive sensor;

tracking, via a second passive sensor on a second platform, the object;

obtaining second angular data of the object relative to the second platform via the second passive sensor;

triangulating a location of the object based on first angular data from the first passive sensor and the second angular data from the second passive sensor and obtaining a smooth and monotonically decreasing closed-from function representative of a range of the object based on its location at a point in time;

performing a polynomial curve fit of the first angular data relative to the smooth and monotonically decreasing closed-form function;

taking a derivative of the polynomial curve fit of angular data to that results a smooth function approximating a range-rate of the object.

16 . The object ranging method of claim 15 , further comprising:

approximating a time-to-go until a collision point between the object and the first platform based, wherein approximating the time-to-go is based on a ratio of range to range-rate.

17 . An object ranging system:

a first platform;

a first passive sensor on the first platform, wherein the first passive sensor is configured to track an object located remotely from the first platform;

first spatial data logic on the first platform to generate first angular data of the object relative to the first platform, wherein the first angular data that is generated is based on raw imagery from the first passive sensor;

first ranging logic on the first platform to determine a location of the object relative to the first platform based on the first angular data;

first wireless communication logic on the first platform;

a second platform configured to move in formation with the first platform;

a second passive sensor on the second platform, wherein the second passive sensor is configured to track the object located remotely from the second platform;

second spatial data logic on the second platform to generate second angular data of the object relative to the second platform, wherein the second angular data that is generated is based on raw imagery from the second passive sensor;

second ranging logic on the second platform to determine the location of the object relative to the second platform based on the second angular data;

second wireless communication logic on the second platform, wherein the first wireless communication logic and the second wireless communication logic establish a wireless link for transfer of data between the first platform and the second platform;

wherein one of the first ranging logic and the second ranging logic derives a range of the object from one of the first platform and the second platform as a closed-form function of time, and thereafter derive a range-rate of the object relative to one of the first platform and the second platform as a function of time;

wherein one of the first ranging logic and the second ranging logic approximates a time-to-go until a collision point between the object and one of the first platform and the second platform, wherein approximation of the time-to-go is based on a ratio of range to range-rate.

18 . The object ranging system of claim 17 , further comprising:

wherein one of the first ranging logic and the second ranging logic generates the range and a range error in response to determination of the location of the object based on the first angular data and the second angular data; and

a state estimator that is provided the range and the range error to create a filtered range;

wherein one of the first ranging logic and the second ranging logic curve fits a filter to a set of polynomial measurements represented by at least, wherein performing the curve fitting results in the closed-form function of time.

19 . The object ranging system of claim 17 , further comprising:

a message data type that is shared across the wireless link, wherein the message data type is representative of a warning track of the object; wherein the sharing of the message data types occurs continuously between the first platform and the second platform for a period of time;

wherein the message data type representative of the warning track of the object includes an indicator of a collision between the object and one of the first platform and the second platform;

wherein the first ranging logic determines whether there is a corresponding warning track of the object located by the second passive sensor on the second platform, wherein determination of whether there is the corresponding warning track is accomplished by determining whether there is an inertially consistent similarity in the corresponding track from the second passive sensor and the warning track from the first passive sensor, and if consistent, then the first angular data and the second angular data are matched to triangulate the location of the object.

Assignments (1)

References Cited (25)