Fast Response Projectile Roll Estimator

• Main Author: TYREE ANTHONY K
• Format: Patent
• Language: English
• Published: 17.03.2011
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

An apparatus and method for estimating a roll angle of a projectile may include a measurement unit outputting roll rate, yaw rate, and pitch rate signals indicative of rotation rates about substantially orthogonal roll, yaw, and pitch axes, the roll axis substantially aligned with a longitudinal axis of the projectile. A controller may sample the roll rate, yaw rate, and pitch rate signals to obtain time sequential roll rate, yaw rate, and pitch rate samples; calculate time sequential cumulative roll estimates by summing the roll rate samples; calculate time sequential gravity vector estimates from the corresponding yaw rate and pitch rate samples; de-roll each gravity vector estimate based on the corresponding cumulative roll estimate; filter the de-rolled gravity vector estimates to determine a filtered initial roll estimate; and add the filtered initial roll estimate to the current cumulative roll estimate to provide a current roll angle estimate.