Six-Degree-of-Freedom Motion Body Model Source Code for Motion Simulation

The six-degree-of-freedom (6-DOF) motion body model is a mathematical framework widely used for simulating complex dynamic systems such as aircraft, vehicles, and marine vessels. This model comprehensively describes an object's translational and rotational movements in three-dimensional space, encompassing displacements along the x, y, and z axes as well as rotations about these axes (pitch, yaw, and roll).

In MATLAB m-file implementations, the system model typically incorporates both dynamic and kinematic equations. The dynamics component involves Newton-Euler equations to calculate how forces and moments influence motion states, while the kinematics component transforms angular and linear velocities into attitude and position changes through integration.

Key implementation phases include:

Parameter Initialization: Defining physical parameters like mass and moment of inertia matrices, along with initial positions, velocities, and attitude quaternions/Euler angles. External Force Inputs: Modeling environmental forces (e.g., gravitational forces, aerodynamic drag) and control forces (e.g., thruster outputs) as vector inputs. Equation Solving: Updating motion states through numerical integration methods like ODE45, with attitude commonly represented using quaternions to avoid gimbal lock issues. Visualization Output: Utilizing MATLAB's graphics capabilities (plot3, quiver3, animatedline) to display trajectory paths and orientation changes in 3D space.

Core challenges involve handling coupled terms (e.g., Coriolis forces) and optimizing numerical stability through appropriate solver selection. For extended applications, the model can integrate with control system designs or external environment simulations (wind fields, water currents) for high-fidelity simulations.