Abstract: In high angular dynamic environments, accelerometer size effect, which is due to the fact that the center of seismic mass(the effective acceleration measurement point) of each accelerometer in the triad could not be physically collocated, becomes a dominant error source for accurate navigation of a Strapdown Inertial Navigation System(SINS). A size effect error model is deduced from a geometric viewpoint. Three kinds of calibration scheme based on a precise triad axis rate turntable are devised, namely the constant angular rate rotation, the constant angular acceleration one and the sine angular acceleration one. A Kalman filter for processing the velocity measurements of the SINS during rotation is formulated to estimate the size effect coefficients. Through the observability analysis of piece wise constant system (PWCS), the error model under three different calibration motions are all completely observable. The simulation results validate all the calibration schemes’ feasibility and indicate that the first motion results in the most smooth estimate process while the third one promises the best estimation accuracy.

Key words: Strapdown inertial measurement unit(SIMU), Accelerometer size effect(inner lever arm effect), Calibration, Kalman filtering