Research on INS/CNS integrated navigation error model

The INS/CNS integrated navigation method based on the Strapdown Inertial Measurement Unit and Star Sensor combines the advantages of the two navigation methods, which can achieve high dynamics and high accuracy of integrated navigation. The system error model of traditional INS/CNS integrated navigation strapdown installation needs to linearize the inertial misalignment angle and the installation errors of inertial and star sensors, and establish high-order observation equations. When the installation error is large, it will affect the accuracy of misalignment angle, thereby affecting the effectiveness of integrated navigation. This article focuses on the characteristics of INS/CNS strapdown installation systems and studies a linear error model with only inertial misalignment angle. The effectiveness of the model method is demonstrated through mathematical simulation, and the accuracy of the misalignment angle is calculated. In the process of solving the misalignment angle in this model, there is no need to separate installation errors, which reduces system complexity.