Navigation aids for unmanned aerial systems in a gps-denied environment

Patent metadata

Field	Value
Publication number	US-2018010914-A1
Application number	US-201715592001-A
Country	US
Kind code	A1
Filing date	May 10, 2017
Priority date	Jul 5, 2016
Publication date	Jan 11, 2018
Grant date	—

Abstract

Example navigation aids for increasing the accuracy of a navigation system are disclosed herein. An example method disclosed herein identifying, with an aircraft intent description language (AIDL) aid, an AIDL instruction as associated with a first dynamic activity level of a plurality of dynamic activity levels and determining, with the AIDL aid, an aircraft state to be affected by the AIDL instruction. The example method also includes changing, with a navigation filter, a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft and estimating, with the navigation filter, a trajectory of the aircraft based on the weighting scheme and the measurement.

First claim

What is claimed is:

1 . A method comprising:
identifying, with an aircraft intent description language (AIDL) aid, an AIDL instruction as associated with a first dynamic activity level of a plurality of dynamic activity levels; determining, with the AIDL aid, an aircraft state to be affected by the AIDL instruction; changing, with a navigation filter, a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft; and estimating, with the navigation filter, a trajectory of the aircraft based on the weighting scheme and the measurement.

2 . The method of claim 1 , wherein the plurality of dynamic activity levels include the first dynamic activity level and a second dynamic activity level, the first dynamic activity level associated with a high dynamic activity and the second dynamic activity level associated with a low dynamic activity.

3 . The method of claim 2 , wherein changing the weighting scheme for the measurement includes assigning a lower weight to the measurement.

4 . The method of claim 1 , wherein the navigation filter includes an Extended Kalman Filter (EKF), and wherein changing the weighting scheme for the measurement includes increasing or decreasing a covariance factor of the measurement in at least one of a process noise matrix Q or a measurement noise matrix R of the EKF.

5 . The method of claim 1 , wherein the measurement is a first measurement, further including:
generating an internal dynamic model of the aircraft; and determining a second measurement for the aircraft state based on the internal dynamic model.

6 . The method of claim 5 , wherein changing the weighting scheme for the first measurement includes assigning a higher weight to the second measurement.

7 . The method of claim 1 , wherein identifying the AIDL instruction as a high dynamic activity includes:
comparing a maneuver associated with the AIDL instruction to a threshold; and identifying the AIDL instruction as the first dynamic activity level based on the comparison.

8 . The method of claim 1 further including determining when the aircraft is in a GPS-denied environment.

9 . The method of claim 8 further including changing the weighting scheme for the measurement of the aircraft state in response to the aircraft being in the GPS-denied environment.

10 . The method of claim 1 , wherein the navigation filter estimates the trajectory of the aircraft without an absolute position measurement.

11 . An aircraft comprising:
an inertial navigation system (INS) to obtain a measurement of an aircraft state; an aircraft intent description language (AIDL) aid to identify an AIDL instruction of an aircraft as associated with a dynamic activity level, the aircraft state affected by the AIDL instruction; and a navigation filter to change a weighting scheme for the measurement of the aircraft state and estimate a location of the aircraft based on the weighting scheme and the measurement.

12 . The aircraft of claim 11 , wherein the navigation filter is to change the weighting scheme for the measurement by assigning a lower weight to the measurement if the dynamic activity level is a high dynamic activity level.

13 . The aircraft of claim 11 , wherein the navigation filter includes an Extended Kalman Filter (EKF), and wherein the EKF is to increase or decrease a covariance factor of the measurement in at least one of a process noise matrix Q or a measurement noise matrix R of the EKF.

14 . The aircraft of claim 11 , wherein the navigation filter estimates the location of the aircraft without an absolute position measurement.

15 . The aircraft of claim 11 , wherein the INS includes at least one of an accelerometer, a gyroscope, a magnetometer, a static pressure sensor, a dynamic pressure sensor or a temperature sensor.

16 . A tangible computer readable storage medium comprising instructions that, when executed, cause a machine to at least:
identify an AIDL instruction as associated with a high dynamic activity; determine an aircraft state to be affected by the AIDL instruction; change a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft; and estimate a trajectory of the aircraft based on the weighting scheme and the measurement.

17 . The tangible computer readable storage medium of claim 16 , wherein the measurement is a first measurement, the instructions further to cause the machine to:
generate an internal dynamic model of the aircraft; and determine a second measurement for the aircraft state based on the internal dynamic model.

18 . The tangible computer readable storage medium of claim 17 , wherein the instructions, when executed, cause the machine to change the weighting scheme for the first measurement by assigning a higher weight to the second measurement.

19 . The tangible computer readable storage medium of claim 16 , wherein the instructions, when executed, are to identify the aircraft AIDL instruction as the high dynamic activity by:
comparing a maneuver associated with the AIDL instruction to a threshold; and identifying the AIDL instruction as the high dynamic activity based on the comparison.

20 . The tangible computer readable storage medium of claim 16 , wherein the instructions, when executed, cause the machine to estimate the trajectory of the aircraft without an absolute position measurement.

Assignees

• Boeing Co

Inventors

• Hardt Michael W
• Gallo Eduardo
• Navarro Francisco A
• Bushnell Glenn Scott

Classifications

• B64U2201/10

  autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS] · CPC title

• G01C23/00

  Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration · CPC title

• B64C19/00

  Aircraft control not otherwise provided for · CPC title

• G01C21/165

  combined with non-inertial navigation instruments · CPC title

• G01C21/188

  for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems · CPC title