Transfer alignment of navigation systems
View Patent ↗Navigation systems provide accurate position, velocity and attitude information at one or more slave inertial measurement units (SIMU), mounted and spaced apart from a master inertial navigation system (MINS).
1. A method for determining position or velocity or orientation of a slave inertial measurement unit (SIMU) linked to a vehicle system and to a master inertial navigation system (MINS) comprising: obtaining velocity, and body angular rate information in the navigation coordinate frame from said MINS, integrating the MINS velocity and MINS body angular rate information to produce the integral of MINS velocity and MINS body angular rate, comparing the integral of MINS velocity and MINS body angular rate to the integrals of velocity and body angular rate of said SIMU, determining and applying corrections to SIMU position, velocity and orientation at said SIMU.
2. The method of claim 1 further comprising adjusting the MINS integrals of velocity and MINS position information for nominal lever arm compensation, where the lever arm links said MINS and said SIMU.
3. The method of claim 1 or claim 2 further comprising using MINS wander angle information and MINS position information to determine position, velocity or orientation of said SIMU.
4. A method for determining position or velocity or orientation of a slave inertial measurement unit (SIMU) linked to a vehicle system and to a master inertial navigation system (MINS) comprising: obtaining velocity, and body angular rate information in the navigation coordinate frame from said MINS, integrating the MINS velocity and MINS body angular rate information to produce the integral of MINS velocity and MINS body angular rate, comparing the integral of MINS velocity and MINS body angular rate to the integrals of velocity and body angular rate of said SIMU, determining and applying corrections to SIMU vehicle rate or earth rate or earth radius of curvature.
5. A transfer alignment system for a vehicle that includes at least one master inertial navigation system (MINS) linked to said vehicle and to at least one slave inertial measurement unit (SIMU) comprises means for obtaining the integral of MINS velocity and MINS body angular rate information and the navigation coordinate frame from said MINS, and means for comparing the integral of MINS velocity and MINS body angular rate to the integrals of velocity and body angular rate of said SIMU to determine corrections to apply to SIMU position, velocity and orientation at said SIMU.
6. The system of claim 5 further comprising means for adjusting the MINS integrals of velocity and MINS position information for nominal lever arm compensation, said system including a lever arm linking said MINS to said SIMU.
7. The system of claim 5 or claim 6 further comprising means for obtaining MINS wander angle information and MINS position information, and means for using said MINS wander angle information and said MINS position information to determine position, velocity or orientation of said SIMU.