6-DOF Flight Dynamics Simulator

Overview

This repository contains a modular, high-fidelity, 6-Degree-of-Freedom (6-DOF) flight dynamics simulation engine. The architecture is engineered for advanced stability and control analysis, full-state trajectory integration, and comprehensive numerical linearization across the flight envelope.

Key Capabilities

• Modular Environmental Models: Decoupled environmental definitions allow for swapping Earth models and wind field models with just the job configuration.
• WGS-84 Ellipsoidal Earth Model: Incorporates the J2 gravity model, local radii of curvature (meridian and prime vertical), transport rates, and Coriolis accelerations to support highly accurate navigation frame (NED) kinematics.
• Quaternion Kinematics: Utilizes an Euler parameter (quaternion) formulation for rigid-body rotation to inherently prevent mathematical singularities at extreme pitch angles.
• Non-Linear Trim Solver: Features a highly constrained scipy.optimize (SLSQP) routine for establishing equilibrium flight conditions.
• Numerical Linearization & Analysis: Extracts local linear state-space models ($A$ and $B$ matrices) via central finite differencing. Includes modular routines for eigenvalue extraction, mode shape analysis, and linear response modeling.

System Architecture

• main.py: Primary execution script handling initialization, job execution, and output dispatch.
• src/utils/config_parser.py: Robustly handles job configuration parsing into standardized simulation instructions and variables.
• src/engine/eom_solver.py: Core rigid-body equations of motion.
• src/engine/trim_solver.py: Optimization routines enforcing kinematic constraints for algorithmic trimming.
• src/engine/linearization.py: Perturbation-based state-space derivation and frequency-domain stability analysis.
• src/utils/: Helper modules, unit conversions, plotting classes, and constants.
• models/: Vehicle models. Current implementation supports DAVE-ML vehicles as well as custom vehicle implementations.
• models/X15/: Encapsulates the X-15 aerodynamic database.

Dependencies

Execution requires a standard scientific Python environment. Core dependencies include:

• numpy
• scipy
• matplotlib
• numba
• control
• pyJanus

Execution

The framework is configuration-driven. Execute simulations by passing a directory path containing a config.yaml file to the primary script:

python main.py jobs/<your_job_directory>