Theory of Operation for VRX

The most up-to-date description of the environmental model and vehicle model used in VRX can be found in our paper Toward Maritime Robotic Simulation in Gazebo.

Implementation Notes

This section relates the theoretical model given in the paper above to our current implementation. Any known discrepancies between the theory and implementation are also documented here.

Wind Model

• Our wind model has not yet been ported from VRX Classic. The current wind model relies on the Gazebo built in plugin gz::sim::systems::WindEffects.

Wave Model

The Pierson-Moskowitz spectrum given in the paper is implemented by the wavefield plugin when the model parameter is set to `PMS'. The user can specify a sea state by passing in desired values for the following parameters (the corresponding variable names and description from the paper are given in parentheses):

• period ($T_p$, "peak period")
• gain ($K_H$, "wave height gain")
• direction ($\theta$, "mean wave direction")
• steepness ($q$, "wave steepness")