This project implements equations of motion for rigid bodies.
Often aircraft can be assumed to be rigid and are consequently modeled with rigid body equations of motion.
The Simulink blocks in rigidBody_lib are based on Matlab functions which are named rigidBodyKinetics and rigidBodyKinematicsQuat.
- You need LADAC
Run the test function
rt = table(runtests('rigidBodyUnitTest'))
Have a look at the Simulink blocks and at the Matlab functions.
Here are the naming conventions of the variables and Simulink signal names:
Indices Naming Convention:
Indices are added to the names after an underscore _.
| Index | Explanation |
|---|---|
| b | Body-fixed frame with forward-right-down convention, with the origin at the center of gravity |
| g | Geodetic frame with north-east-down convention, with the origin at the center of gravity |
| K | Motion of the body with respect to the earth |
Signal/Variable Names:
| Signal name | Explanation |
|---|---|
| R_b | Force vector represented in body-fixed frame (3x1 array), in N |
| Q_b | Moment vector with respect to the center of gravity represented in body-fixed frame (3x1 array), in Nm |
| I_b | Inertia matrix represented in body-fixed frame (3x3 array), in kg.m^2 |
| m | Mass of the body (scalar), in kg |
| g | Gravitational acceleration (scalar), in m/s^2 |
| V_Kg | Velocity of the center of gravity relative to the earth represented in geodetic frame (3x1 array), in m/s |
| V_Kb | Velocity of the center of gravity relative to the earth represented in body-fixed frame (3x1 array), in m/s |
| V_Kb_dt | Time-derivative of V_Kb (3x1 array), in m/s^2 |
| s_g | Position with respect to the initial position represented in geodetic frame (3x1 array), in m |
| s_g_dt | Time-derivative of s_Kg, in m/s |
| omega_Kb | Angular velocity of the rigid body relative to the earth represented in body-fixed frame (3x1 array), in rad/s |
| omega_Kb_dt | Time-derivative of omega_Kb (3x1 array), in rad/s^2 |
| q_bg | Quaternion from geodetic frame (g) to body-fixed frame (b) (3x1) |
| q_bg_dt | Time-derivative of q_bg |
| EulerAngles | Euler angles (roll, pitch, yaw) (3x1 array), in rad |
| M_bg | Rotation matrix from geodetic frame (g) to body-fixed frame (b) (3x3 array) |