6-DOF Flight Simulation

Features

• Physics engine — forces, moments, and full state propagation
• Numerical integration — Euler and Runge-Kutta 4th order (RK4)
• Atmosphere model — temperature and pressure vs. altitude (Standard Atmosphere 1976)
• Wind models — simple wind field and linear altitude decay model
• Direction Cosine Matrix (DCM) — body-to-NED frame 3D rotation transforms
• Type-safe physical units — dedicated types for velocity, force, mass, angle, time, etc.
• React + TypeScript + Tailwind — UI scaffold for visualization

Reference diagrams for the governing equations are in public/.

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Prerequisites

• Node.js v18 or later
• npm or yarn

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Setup

git clone https://github.com/wyattcast44/6dof
cd 6dof
npm install   # or: yarn

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Development

npm run dev # or yarn dev

Opens a Vite dev server with hot reload at http://localhost:5173.

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Available Scripts

Command	Description
npm run dev	Start dev server
npm run build	Type-check + production build
npm run preview	Preview production build locally
npm run test	Run tests in watch mode
npm run coverage	Generate test coverage report

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Project Structure

src/
  core/                   # Physics simulation engine
    aircraft/             # Aircraft model and aerodynamic properties
    atmosphere/           # Standard Atmosphere 1976 model
    numerical/            # State vector, Euler integrator, RK4
    sim/                  # Simulation loop (FixedTimeSimulation)
    transforms/           # DCM body/NED rotation transforms
    wind/                 # Wind field and decay models
    gravity/              # Gravity model
    environment/          # Combined environment (atmosphere + gravity + wind)
    flight/               # Flight dynamics interfaces
    vectors/              # Body/NED/position/velocity vector types
    <units>/              # Type-safe unit types (velocity, force, mass, angle, …)
  ui/                     # React UI layer
    App.tsx
    main.tsx
public/                   # Reference diagrams and sample data
  eqs.png                 # Core equations
  translational-eqs.png
  rotational-eqs.png
  components.png
  f16.json                # F-16 sample aerodynamic data

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Architecture Overview

StateVector
  └─> AircraftDynamicsModel   (forces + moments → accelerations)
        └─> Integrator        (Euler or RK4)
              └─> FixedTimeSimulation loop

Environment provides the aircraft model with:

• Atmospheric conditions (density, pressure, temperature) at current altitude
• Gravitational acceleration
• Wind vector at current position

Aircraft is configured via AircraftProperties — mass, wing area, moment of inertia, and stability/control derivatives. See src/core/aircraft/AircraftPropertiesReference.md for a detailed guide to all aerodynamic parameters.

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Testing

npm run test       # watch mode
npm run coverage   # coverage report

Test files cover: state vectors, atmosphere model, wind models, DCM transforms, and the simulation loop.