改进的格网惯导系统无阻尼综合校正方法

综合校正技术可作为抑制格网惯导系统（INS）导航误差的有效手段。加速度计零偏所造成的水平姿态误差是导致综合校正中陀螺漂移估计精度受限的重要因素。针对这一问题，提出了一种改进的无阻尼综合校正方法。首先，推导了格网坐标系框架下估计加速度计零偏和姿态的目标函数；其次，介绍了无阻尼条件下综合校正的两个核心方程；最后设计了无阻尼两点校策略。综合校正前，在多普勒计程仪（DVL）提供的速度辅助下完成加速度计零偏的估计和补偿，以此消除加速度计零偏所造成的水平姿态误差对综合校正中陀螺漂移估计精度的影响。在两次间断的外部位置和航向辅助下通过所设计的综合校正策略完成对陀螺漂移的估计。校正策略中所涉及的水平姿态误差在DVL辅助下由参数估计方法估计得到。仿真及实验结果表明：与现有的研究相比，所设计的综合校正方案进一步减少了DVL的辅助时间，同时由于准确地估计和补偿了加速度计零偏，陀螺漂移的估计精度显著提高，该方案在抑制导航误差方面具备更明显的优势。

Improved non-damping comprehensive calibration method for grid INS

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.