Strapdown inertial navigation system of a rotating carrier

The paper deals with a strapdown inertial navigation system (SINS) of a rotating carrier (RC) characterized by a high roll speed and rather slow oscillations in the yaw and pitch angles. It is shown that it is expedient for an RC to develop four orientation parameters: traditional yaw angles, pitch and trigonometric functions of the sine, cosine of the angle of heel. It analyzes the methods to update information on the absolute angular velocity vector of the RC. A traditional orthogonal measurement base is used when using sensors with the required angular velocity measurement range, while otherwise it is oblique-angled. The paper presents a split scheme of the SINS orientation algorithm, which allows the trigonometric functions of the sine and the cosine to be calculated on the basis of a high order algorithm, and the yaw and pitch angles cosine to be calculated on the basis of a simplified one.