MATLAB Implementation of Strapdown Inertial Navigation System Simulation

In this article, we discuss the simulation program for Strapdown Inertial Navigation Systems (SINS) applied to general aircraft. We select the geographic coordinate system as the navigation frame and implement mechanical arrangement with numerical simulation based on north-referenced navigation principles. The implementation involves coordinate transformation algorithms, inertial measurement unit (IMU) data integration, and navigation solution computation using Runge-Kutta or similar numerical methods. Additionally, we examine guidance system design for ballistic missiles, creating standard trajectories through ballistic equations and comparing perturbation guidance (which uses pre-calculated deviation tables) with explicit guidance (which employs real-time trajectory calculations). Based on comprehensive analysis, we select explicit guidance for its superior flexibility and adaptability, implementing it with required velocity increment as the cutoff function to control engine shutdown for precise target impact. The simulation incorporates guidance law algorithms, cutoff condition monitoring, and trajectory correction modules. Overall, we provide detailed explanations on using the SINS simulation program to achieve these objectives, ensuring system accuracy through error modeling, Kalman filtering integration, and reliability verification via Monte Carlo simulations.