High-Precison In-flight Attitude Estimation Algorithm For Missile

A nonlinear inertial navigation system (INS) attitude estimation method is proposed, which is based on the modified-Rodrigues parameter. The close-loop Kalman Filter is designed to achieve the full-attitude and non-singular attitude estimation, with the satellite navigation data used as the observable quantity. The accuracy of the proposed method is higher than the traditional attitude estimation method using misalignment angle and quaternion error.