6-DoF MODEL FINE-TUNING: AERODYNAMIC COEFFICIENTS, QUATERNIONS AND NUMERICAL SCHEMES

Abstract

This paper addresses key challenges in 6-DoF projectile trajectory simulation using VTraj, a software developed by the Royal Military Academy of Belgium and compliant with NATO’s AEP-96 standard. It focuses on the critical importance of aerodynamic coefficient interpolation, quaternion normalization, and numerical scheme selection to ensure accurate trajectory prediction. The study highlights that selecting an appropriate integration frame eliminates the need for explicit quaternion normalization, preserving numerical stability. Aerodynamic coefficient interpolation is shown to significantly impact accuracy, with drift discrepancies of up to 6% depending on the interpolation method. Finally, a comparison of numerical schemes reveals that the 4th-order Runge-Kutta (RK4) method achieves nearly the same accuracy as the higher-order RK78, while reducing computational time by a factor of at least 1.8. This work provides valuable insights for researchers conducting high-fidelity exterior ballistics simulations.