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Caution: This package is an active development project

Overview

Gazebo plugins to support simulation of Unmanned Surface Vehicles (USVs).

Available Plugins

usv_gazebo_dynamics_plugin

Generates hydrodynamic forces and torques for a twin-hull catamaran vessel with differential drive.

Parameters

waterLevel (double, default: 0.5)

• Altitude of the water level used to calculate buoyancy forces. Positive is up from Z=0.0. [m]

waterDensity (double, default: 997.8)

• Density of the fluid [kg/m^3]

xDotU (double, default: 5.0)

• Added mass in the surge direction. [kg]

xDotV (double, default: 5.0)

• Added mass in the sway direction. [kg]

nDotR (double, default: 1.0)

• Added mass in the yaw direction. [kg m^2]

xU (double, default: 20.0)

• Linear drag in the surge direction [N/(m/s)]

xUU (double, default: 0.0)

• Quadratic drag in the surge direction [N/(m/s)^2]

yV (double, default: 20.0)

• Linear drag in the sway direction [N/(m/s)]

yVV (double, default: 0.0)

• Quadratic drag in the sway direction [N/(m/s)^2]

zW (double, default: 20.0)

• Linear drag in the heave direction [N/(m/s)]

kP (double, default: 20.0)

• Linear drag in the pitch direction [Nm/(rad/s)]

mQ (double, default: 20.0)

• Linear drag in the roll direction [Nm/(rad/s)]

nR (double, default: 20.0)

• Linear drag in the yaw direction [Nm/(rad/s)]

nRR (double, default: 20.0)

• Quadratic drag in the yaw direction [Nm/(rad/s)^2]

maxCmd (double, default: 1.0)

• Assumes that the Drive message (see http://wiki.ros.org/kingfisher_msgs) is +/-F, where F is the maxCmd.

maxForceFwd (double, default: 100.0)

• Maximum forward force for a in the +x thruster [N]

maxForceRev (double, default: -100.0)

• Maximum forward force for a in the -x thruster [N]

boatArea (double, default: 0.48)

• Horizontal surface area of the boat. Assumed to be constant with draft and used for buoyancy calculation [m^2]

boatWidth (double, default: 1.0)

• Width between the thrusters on the vessel - used for calculating the applied torque [m]

boatLength (double, default: 1.35)

• Length of the vessel. The thrust is applied at the rear of the vessel by taking half of the boat length [m]

thrustOffsetZ (double, default: -0.01)

• Offset in the Z direction, relative to CG, for applying the thrust. Causes thrust to couple with pitch and roll [m].

metacentricLength (double, default: 0.4)

• Longitudinal (along x-axis) metacentric height [m]. Results in a stabilizing righting moment in the pitch direction and dictates the natural frequency in pitch.

metcentricWidth (double, default: 0.4)

• Transverse (along y-axis) metacentric height [m]. Results in a stabilizing righting moment in the roll direction and dictates the natural frequency in roll.

Xacro Files

The included urdf/usv_gazebo_dynamics_plugin.xacro file sets all of the parameters for the plugin, intended as a example for customization.

Examples

• Gazebo Simulation of Kingfisher/Heron USV Simplest example of using the USV dynamics plugin in an empty Gazebo world.