System for multiple navigation components

• US 8,224,574 B2
• Filed: 05/09/2005
• Issued: 07/17/2012
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Guidance & Electronics Co., Inc. (Northrop Grumman Corporation)
• Inventors: Tazartes, Daniel A., Volk, Charles H., Huddle, James R., Lipman, Jerome S.
• Primary Examiner(s): Mawari, Redhwan K
• Application Number:
  US11/124,724
• Publication Number:
  US 20050256637A1
• Time in Patent Office: 2,626 Days
• Field of Search: 701/214, 701/220, 701/3, 701/469, 701/466, 701/472, 701/500, 701/473, 701/480, 701/479, 709/208, 700/3, 342/357.2, 342/357.59, 244/3.1, 244/3.2
• US Class Current: 701/500
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

An exemplary navigation system uses a master navigation component at a first location in a vehicle and a slave navigation component at a second location that is a variable displacement to the first location due to physical deformation of the vehicle. Static and dynamic location components provide static and dynamic information of the displacement between the first and second locations. An error estimator estimates errors in the navigational measurement data generated by the slave navigation component based on the navigational measurement data generated by the master navigation component and the displacement information provided by the static and dynamic location components. The master navigation component corrects the navigation measurement data of the slave navigation component based on the determined error and translates the corrected navigation measurement data of the slave navigation component into navigational measurement data in its coordinate system.

Claims

1. An apparatus, comprising:

a master navigation component determines navigation measurement data in a first coordinate system; and

one or more slave navigation components that determine navigation measurement data of the one or more slave navigation components each in their own secondary coordinate system;

wherein the master navigation component is disposed at a first location in a vehicle and a first one of the slave navigation components is disposed at a second location in the vehicle, the first and second coordinate systems being associated with the first and second locations, respectively;

wherein the one or more slave navigation components provide the navigation measurement data of the one or more slave components each in their own secondary coordinate system to the master navigation component;

wherein the master navigation component compares the navigation measurement data of the one or more slave components each in their own secondary coordinate system to navigation measurement data for the master navigation component in the first coordinate system, the master navigation component and the slave navigation components obtaining measurement data using the same type of measuring instruments and without information being received from a source outside of the vehicle;

wherein the master navigation component translates the navigation measurement data of the one or more slave navigation components in the second coordinate system into navigation measurement data of the one or more slave navigation components in the first coordinate system;

a portion of the vehicle between the first location with the master navigation component and the second location with the first one of the slave navigation components defining a corresponding lever arm;

a dynamic location component coupled to the master navigation component wherein the dynamic location component provides dynamic information during bending of the lever arm between the first and second locations due to bending of said portion of the vehicle, the displacement between the first slave navigation component and the master navigation component changing due to physical deflection of the second location relative to the first location, the master navigation component estimating the error in the navigation measurement data of the first slave navigation component at the second location based on the dynamic displacement information during bending of the lever arm due to bending of the vehicle;

the master navigation component correcting the navigation measurement data of the first one of the slave navigation components based on the estimated errors due to bending of the portion of the vehicle defining the lever arm;

a static location component coupled to the master navigation component wherein the static location component provides static navigation information based on the distance between the first and second locations while the vehicle is not undergoing bending, the master navigation component estimates the error in the navigation measurement data of the first slave navigation component at the second location based on the static distance information;

a summation element that receives inputs from the static location component and the dynamic location component, the summation element providing an output that provides estimates of error in the navigation measurement data of the second coordinate system relative to the first coordinate system based on the dynamic displacement data and static navigation information.

2. The apparatus of claim 1 wherein the master navigation component and the one or more slave navigation components are one of accelerometers and gyroscopes.

3. The apparatus of claim 2 wherein the master navigation component estimates errors in the navigation measurement data of the one or more slave navigation components through employment of a Kalman filter.

4. The apparatus of claim 2 wherein the master navigation component corrects the navigation measurement data of the one or more slave navigation components each in their own secondary coordinate system based on the estimated errors.

5. The apparatus of claim 1 wherein the master navigation component corrects the navigation measurement data of the first slave navigation component based on the static distance and dynamic displacement information.

6. The apparatus of claim 5 wherein the master navigation component translates the navigation measurement data of the first slave navigation component in the second coordinate system into navigation measurement data in the first coordinate system based on the navigation measurement data corrected for static and dynamic displacement information.

7. The apparatus of claim 1 wherein the master and slave navigation components each includes a time synchronization component that encodes master and slave navigation measurement data with time information so that master and slave measurement data as of substantially the same time can be utilized in estimating the error in the navigation measurement data of the first slave navigation component at the second location based on the dynamic displacement information.

8. A method for determining navigation information comprising the steps of:

generating master navigation measurement data by a master navigation component with a first coordinate system at a first location in a vehicle;

generating slave navigation measurement data by a slave navigation component with a second coordinate system in a second location in the vehicle, a portion of the vehicle between the first and second locations defining a lever arm, the master navigation measurement data and the slave navigation measurement data being obtained using the same type of measuring instruments and without information being received from a source outside of the vehicle;

determining dynamic information for displacement changes between the first and second locations during physical deflection of the lever arm due to bending of the portion of the vehicle;

determining static information by a static location component coupled to the master navigation component wherein the static information is based on the distance between the first and second locations while the vehicle is not undergoing bending;

estimating error in the slave navigation measurement data at the second location based on the static distance information;

receiving the static information and the dynamic information;

providing an estimation of errors in the slave navigation measurement data based on the master navigation measurement data and summation of the dynamic displacement information and the static information;

correcting the slave navigation measurement data based on the estimated errors;

translating the corrected slave navigation measurement data into navigation measurement data in the first coordinate system;

determining at least one of velocity, position and orientation of the vehicle based on the corrected slave navigation measurement data.

9. The method of claim 8 wherein the master navigation measurement data and the slave navigation measurement data are one of acceleration and gyroscopic data.

10. The method of claim 8 further comprising the step of encoding master and slave navigation measurement data with time information so that master and slave measurement data as of substantially the same time is used in estimating the error in the navigation measurement data of the first slave navigation component at the second location based on the dynamic displacement information.