The effect of carouseling on MEMS IMU performance for gyrocompassing applications

The concept of carouseling an IMU is simulated in order to improve the accuracy of MEMS IMUs. Carouseling consists of slewing the IMU through a pre-determined trajectory that is selected based on inherent properties that lead to improved performance. MEMS devices typically have far more uncertainty than standard inertial measurement devices, yet are considerably less massive and require less power, so implementing this carouseling scheme could make the use of these lightweight systems possible even in high-accuracy situations, such as gyrocompassing. In gyrocompassing, the most significant benefit provided by the carouseling scheme is the reduction in the error contribution of gyroscope bias, as this error is almost completely eliminated. Additionally, it was found that although implementing the carouseling scheme required the addition of error states to account for the size effect, in many cases these error states may not be necessary. Overall, the carouseling of the MEMS IMUs was shown to be effective in reducing azimuth error covariance significantly. Thesis Supervisor: Matthew Bottkol Title: Charles Stark Draper Laboratory Thesis Supervisor: Emilio Frazzoli Title: Associate Professor of Aeronautics & Astronautics Acknowledgments First I would like to thank the Charles Stark Draper Laboratory and the Massachusetts Institute of Technology for giving me such an incredible opportunity to broaden my academic horizons. I am profoundly grateful that I had the privilege to attend the most prestigious engineering school in the world and work for one of the most respected labs in aerospace. I would like to thank my thesis advisor Matthew Bottkol for his dedicated support and invaluable guidance during the creation of this thesis. In addition, I would like to thank Olivier de Weck and Emilio Frazzoli, my advisors at M.I.T. who provided me with wisdom and encouragement along the way. Numerous professors and personell at M.I.T., the University of Missouri, and Draper provided me with innumerable amounts of help that assisted me on my journey, and a special thanks goes to the late Michael Ash, who I never had the pleasure to meet, but who did me the great service of bringing me in to the Draper Laboratory. I thank my parents, Angela and Matthew Renkoski for almost 25 years of unwavering support and love. They taught me the benefits of hard work and instilled in me the drive to succeed and do my best in all my endeavors. There is no doubt I never would have accomplished the completion of this thesis if not for their positive and nurturing influence. A great amount of thanks goes to all my family and friends for the encouragement and kindness they have constantly shown me. I can not imagine a more caring or thoughtful group of people to help me through my thesis or my life. In particular I would like to thank Julie Haesemeier for her unconditional support and dedication. Throughout this thesis writing process she kept my spirits high and was a constant source of inspiration. This thesis was prepared at The Charles Stark Draper Laboratory under IR&D and Contract GC 009256, sponsored by the United States Army Night Vision and Electronic Sensors Directorate at Ft. Belvoir, VA. Publication of this thesis does not constitute approval by Draper or the sponsoring agency of the findings or conclusions contained herein. It is published for the exchange and stimulation of ideas. THIS PAGE INTENTIONALLY LEFT BLANK