LAUSR

The system reset algorithms realized in damping state rely heavily on the output of Doppler Velocity Log (DVL). Aiming at shipborne grid Strap-down Inertial Navigation System (SGSINS), this paper addresses a non-damping system reset algorithm to estimate the gyroscope drifts. First, SGSINS is integrated with DVL to estimate the horizontal attitude errors, and the estimation results are introduced to the system reset. Next, to ensure P equation can be utilized to design the non-damping system reset scheme, P equation is reformulated by reserving the horizontal attitude errors as the correction terms. Finally, under the assistance of two intermittent or short continuous external yaw and position, the two-point and optimum system reset schemes are designed based on the Ψ equation and P equation. Simulation results indicate the algorithm can estimate the gyroscope drifts accurately in non-damping state. Compensating the gyroscope drifts can efficiently suppress the drifted errors in SGSINS. Because it takes a short time to estimate the horizontal attitude errors, compared with the existing algorithms realized in damping state, the proposed algorithm greatly shortens the time of using DVL, and this improves the reliability of the algorithm in practical application.