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Performance Improvements for the Lunar Reconnaissance Orbiter Gyroless Extended Kalman FilterIn late 2017, the laser intensity monitor (LIM) current began to decline on the Lunar Reconnaissance Orbiter (LRO) miniature inertial measurement unit (MIMU). The MIMU was powered off in March 2018 and has only been used during extended eclipses, a pre-eclipse orbit phasing maneuver, and critical momentum unloads. Science slews were suspended, and the onboard extended Kalman filter (EKF) was disabled. A coarse rate was estimated through star tracker quaternion differentiation, and attitude was provided directly from a single star tracker. A complementary filter, combining the differentiated quaternions with the integrated acceleration derived from the attitude control torque, was developed, tested, and uploaded to the spacecraft in December 2018. The EKF has been enabled, using the complementary filter rate in place of the MIMU and science slews are now being performed. This paper presents an overview of the complementary filter rate estimation and EKF changes, fault detection updates without the MIMU, and inflight performance improvements.
Document ID
20190029118
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Halverson, Julie
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Hsu, Oscar
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Calhoun, Philip
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Tedla, Yohannes
(KBRwyle Greenbelt, MD, United States)
Date Acquired
August 16, 2019
Publication Date
August 11, 2019
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
AAS-19-615
GSFC-E-DAA-TN67054
Report Number: AAS-19-615
Report Number: GSFC-E-DAA-TN67054
Meeting Information
Meeting: 2019 AAS/AIAA Astrodynamics Specialist Conference
Location: Portland, ME
Country: United States
Start Date: August 11, 2019
End Date: August 15, 2019
Sponsors: American Astronautical Society, American Institute of Aeronautics and Astronautics (AIAA)
Funding Number(s)
CONTRACT_GRANT: NNG17HP02C
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
External Peer Committee
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