Tightly coupled trajectory predictor with constant up-finding

Patent metadata

Field	Value
Publication number	US-2022260341-A1
Application number	US-202117179039-A
Country	US
Kind code	A1
Filing date	Feb 18, 2021
Priority date	Feb 18, 2021
Publication date	Aug 18, 2022
Grant date	—

Abstract

Systems and methods for a tightly coupled trajectory predictor with constant up-finding are provided. In certain embodiments, a system includes an inertial measurement unit that provides inertial measurements of a vehicle. The system also includes an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up. Further, the system includes one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.

First claim

What is claimed is:

1 . A system comprising:
an inertial measurement unit that provides inertial measurements of a vehicle; an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up; and one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.

2 . The system of claim 1 , wherein the vehicle is a spinning projectile.

3 . The system of claim 1 , wherein the up-finding measurements comprise a number of non-contiguous time periods when the vehicle is pointing up.

4 . The system of claim 1 , wherein the one or more processors implement a model-based trajectory predictor, wherein the model-based trajectory predictor calculates trajectory predictions based on the up-finding measurements.

5 . The system of claim 4 , wherein the one or more processors use the trajectory predictions to bound the errors in the inertial measurements.

6 . The system of claim 1 , wherein the up-finding sensor acquires the up-finding measurements without communicating with devices not located on the vehicle.

7 . The system of claim 1 , wherein the up-finding measurements are acquired through detecting reflections of an emitted laser and determining at least one of:
whether the reflections are being received; and periodicity of intensity of the detected reflections.

8 . The system of claim 1 , wherein the one or more processors bound the errors in the inertial measurements by comparing a number of detected spins from the up-finding measurements against a number of estimated spins based on the inertial measurements.

9 . The system of claim 1 , wherein the up-finding measurements comprise at least one of:
an indication that the up-finding sensor has pointed towards a particular direction; and a count of a number of times the up-finding sensor has pointed toward the particular direction.

10 . A method comprising:
receiving inertial measurements for motion of a vehicle; providing up-finding measurements based on detections of when a portion of the vehicle is facing a particular direction during the motion of the vehicle; and calculating an integrated navigation solution for the vehicle using the inertial measurements and the up-finding measurements, wherein the up-finding measurements provide a bound for errors in the inertial measurements.

11 . The method of claim 10 , wherein the vehicle is a spinning projectile.

12 . The method of claim 10 , wherein the up-finding measurements comprise a number of non-contiguous time periods when the vehicle is pointing up.

13 . The method of claim 10 , wherein providing the up-finding measurements comprises providing the up-finding measurements to a model-based trajectory predictor, wherein the model-based trajectory predictor calculates trajectory predictions based on the up-finding measurements.

14 . The method of claim 13 , wherein calculating the integrated navigation solution comprises calculating the integrated navigation solution based on the trajectory predictions and the inertial measurements.

15 . The method of claim 10 , wherein the up-finding measurements are acquired by an up-finding sensor that acquires the up-finding measurements without communicating with devices not located on the vehicle.

16 . The method of claim 10 , wherein the up-finding measurements are acquired through detecting reflections of an emitted laser and determining at least one of:
whether the reflections are being received; and periodicity of intensity of the detected reflections.

17 . The method of claim 10 , wherein the up-finding measurements provide the bound for the errors in the inertial measurements by comparing a number of detected spins from the up-finding measurements against a number of estimated spins based on the inertial measurements.

18 . The method of claim 10 , wherein the up-finding measurements comprise at least one of:
an indication that an up-finding sensor making the up-finding measurements has pointed towards the particular direction; and a count of a number of times the up-finding sensor has pointed toward the particular direction.

19 . A system comprising:
an inertial measurement unit that provides inertial measurements of a vehicle; an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up; and one or more processors configured to:
implement a model-based trajectory predictor, wherein the model-based trajectory predictor calculates trajectory predictions based on the up-finding measurements; and
bound errors in the inertial measurements during navigation of the vehicle using the trajectory predictions.

20 . The system of claim 19 , wherein the up-finding sensor acquires the up-finding measurements without communicating with devices not located on the vehicle.

Assignees

• Honeywell Int Inc

Inventors

• Samborski Calvin
• Snyder Scott

Classifications

• G01D1/00

  Measuring arrangements giving results other than momentary value of variable, of general application (G01D3/00 takes precedence; in tariff metering apparatus G01D4/00; transducers not specially adapted for a specific variable G01D5/00) · CPC title

• F41G7/36 Primary

  using inertial references · CPC title

• G01C21/165 Primary

  combined with non-inertial navigation instruments · CPC title

• F41G7/222

  for spin-stabilized missiles · CPC title

• F41G7/2213

  maintaining the axis of an orientable seeking head pointed at the target, e.g. target seeking gyro · CPC title