USV dynamics on Diffboat about usv_sim_lsa HOT 4 OPEN

Hello walidtouzout

In order to apply lift and drag forces using the usv_dynamics_plugin, you should configure the plugin by attaching it to a link.

<plugin name="usv_sail_plugin" filename="libfoil_dynamics_plugin.so">
<link_type>rudder</link_type>
<mult_lift>1.5</mult_lift>
<mult_drag>1</mult_drag>
<cp>-0.2 0 0</cp>
<area>0.02</area>
<fluid_density>1000</fluid_density>
<forward>1 0 0</forward>
<upward>0 1 0</upward>
<link_name>rudder</link_name>
<fluidVelocity>${waterType}</fluidVelocity>
</plugin>

I believe you should develop a plugin to visualize all forces. In last year, I asked for a plugin with this functionality to a OSRF developer and she informed me that it haven't been developed.

Regards,
Marcelo Paravisi

from usv_sim_lsa.

from usv_sim_lsa.

Hi @walidtouzout

you are correct. you have to modify the lift and drag plugin to publish the forces to a topic. then you visualize it using Rviz.

You can use this plugin as an example https://github.com/uuvsimulator/uuv_simulator/blob/master/uuv_gazebo_plugins/uuv_gazebo_ros_plugins/src/FinROSPlugin.cc

they publish the forces on a topic called joint/wrench.

from usv_sim_lsa.

Hi again,
when I was trying to apply Lift/drag forces by configuring the plugin in empty.world file :

<model name="model">
    <link name="link">
           <wind>true</wind>
    </link>
    <plugin name="foil_dynamics_plugin" filename="libfoil_dynamics_plugin.so">
    <link_type>rudder</link_type>
    <mult_lift>1.5</mult_lift>
<mult_drag>1</mult_drag>
<cp>-0.2 0 0</cp>
<area>0.02</area>
<fluid_density>1000</fluid_density>
<forward>1 0 0</forward>
<upward>0 1 0</upward>
<link_name>rudder</link_name>
<fluidVelocity>${waterType}</fluidVelocity>
</plugin>      

I saw in the terminal that the plugin was loaded, but when running a scenario I got this error message:

gzserver: /usr/include/boost/smart_ptr/shared_ptr.hpp:648: typename boost::detail::sp_member_access::type boost::shared_ptr::operator->() const [with T = gazebo::physics::Link; typename boost::detail::sp_member_access::type = gazebo::physics::Link*]: Assertion `px != 0' failed.

and the scenario couldn't be launched, can you help me to solve this problem ?

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