关键词: 格网惯导系统, 加速度计零偏, 陀螺漂移, 无阻尼, 多普勒计程仪

Abstract: The comprehensive calibration technique is an effective method for the suppression of grid Inertial Navigation System (INS) errors. The level attitude errors caused by accelerometer biases are the key factors influencing the estimation accuracy of gyroscope drifts in comprehensive calibration. Aiming at this problem, this paper proposes an improved non-damping comprehensive calibration method. First, the objective function in the grid frame is deduced to estimate the accelerometer biases and level horizontal attitudes. Next, the P equation and ψ equation in a non-damping state are introduced. Finally, a non-damping two-point calibration scheme is designed. Before the calibration, the accelerometer biases are estimated and compensated with the velocity given by the Doppler Velocity Log (DVL). The DVL aims to eliminate the negative effect of the level attitude errors caused by accelerometer biases on the estimation accuracy of the gyroscope drifts. With the assistance of two intermittent external positions and yaw, the gyroscope drifts are estimated by the designed calibration scheme. The involved level attitude errors in the calibration scheme are estimated with the DVL. Simulation results indicate that compared with the existing works, the proposed calibration scheme further reduces the time of DVL dependence. Meanwhile, the satisfying estimation and compensation of accelerometer biases lead to the improvement of the estimation accuracy of the gyroscope drift, exhibiting obvious advantage of this method in suppressing navigation errors.

Key words: grid INS, accelerometer biases, gyroscope drifts, non-damping, DVL