Abstract: Embodiments described herein provide for passive timing of asynchronous Inertial Measurement Unit (IMU) attitude data using information derived from a pattern of skipped and duplicate samples of attitude data generated by the IMU. One embodiment is an attitude controller for a vehicle that generates samples of attitude data at a first frequency (f1) from an IMU of the vehicle. The IMU updates the attitude data at a second frequency (f2). Each update of the attitude data includes a time stamp. The attitude controller is processes time stamps in the samples to identify a pattern of at least one of a skipped sample of an update to the attitude data and a duplicate sample of an update to the attitude data. The attitude controller estimates lag times between updates of the attitude data and samples of the attitude data based on the pattern and a relationship between f1 and f2.

Abstract: Embodiments described herein provide for passive timing of asynchronous Inertial Measurement Unit (IMU) attitude data using information derived from a pattern of skipped and duplicate samples of attitude data generated by the IMU. One embodiment is an attitude controller for a vehicle that generates samples of attitude data at a first frequency (f1) from an IMU of the vehicle. The IMU updates the attitude data at a second frequency (f2). Each update of the attitude data includes a time stamp. The attitude controller is processes time stamps in the samples to identify a pattern of at least one of a skipped sample of an update to the attitude data and a duplicate sample of an update to the attitude data. The attitude controller estimates lag times between updates of the attitude data and samples of the attitude data based on the pattern and a relationship between f1 and f2.