采用四元数方法推导出SDINS数学平台角误差方程和速度误差方程，并以此建立非线性初始对准误差模型，应用扩展卡尔曼滤波(EKF)进行精对准，确定初始失调角。-using quaternion approach derived platform SDINS mathematical equations and the error rate of error equation, and the establishment of this initial alignment error nonlinear model, extended Kalman Filter (EKF) for precision alignment, EASY determine the initial angle.