Missile System Design Project

1 Introduction

This project is a theoretical missile system design effort for educational purposes and portfolio development. It covers the full engineering lifecycle — from requirements and systems modeling to guidance algorithms, aerodynamic analysis, and structural verification.

1.1 Disciplines

• Systems Engineering — SysML modeling, requirements management, architecture
• GNC — Guidance, Navigation, and Control algorithms in MATLAB/Simulink
• Aerodynamics — CFD analysis of external flow and drag characteristics
• Structures — FEM-based structural and thermal analysis
• Mechanical Design — CAD modeling and integration

2 GNC

The GNC subsystem is responsible for steering the missile from launch to target intercept. It is divided into three functional areas: Guidance, Navigation, and Control.

2.1 Guidance

Generates acceleration commands to drive the missile toward the target.

2.1.1 Proportional Navigation

Commands lateral acceleration proportional to the line-of-sight (LOS) rate. The guidance command is:

\[a_c = N' \dot{\lambda} V_c\]

where \(N'\) is the navigation constant, \(\dot{\lambda}\) is the LOS rate, and \(V_c\) is the closing velocity.

2.1.2 Augmented Proportional Navigation

Extends PN by adding a term to account for target acceleration:

\[a_c = N' \dot{\lambda} V_c + \frac{N'}{2} a_T\]

This improves performance against maneuvering targets.

2.2 Navigation

Estimates the missile’s state (position, velocity, attitude) from sensor measurements.

2.2.1 Inertial Measurement Unit

The IMU provides high-rate measurements of body-frame accelerations and angular rates via accelerometers and gyroscopes.

2.2.2 Seeker

The seeker measures the angle between the missile body axis and the line of sight to the target, providing LOS rate information for guidance.

2.2.3 State Estimation

Sensor data is fused using a Kalman filter to produce filtered state estimates for the guidance and control loops.

2.3 Control

Translates guidance commands into fin deflections via autopilot loops.

2.3.1 Pitch and Yaw Loops

Inner-loop rate feedback with outer-loop acceleration tracking to follow guidance commands.

2.3.2 Roll Stabilization

Maintains zero roll rate to keep the pitch and yaw channels decoupled.

2.3.3 Actuator Dynamics

Fin actuators are modeled with bandwidth limits, rate limits, and position saturations.