Using plugin from Gazebo Sim

[ROxX]

I am trying to apply what I am learning to my personal robot. I have successfully been able to spawn the robot in Gazebo Sim. What am not able to understand is how to use the plugins available in the on line library - Gazebo Sim: gz::sim::systems Namespace Reference

I want to use the mecanum wheel plugin Gazebo Sim: MecanumDrive Class Reference

In the class the plugin begins with

What is unclear is how to format that for mecanum drive, even the diff drive in the on-line reference is different

If you help me, would greatly appreciate it.

[girishkumar.kannan]

Hi @ROxX ,

This page provides proper guidelines to properly migrate from Ignition to Gazebo Sim.

This is how you configure the Mecanum Drive Controller plugin :

    <!-- Mecanum Drive Controller Gazebo Plugin -->
    <gazebo>
        <plugin filename="gz-sim-mecanum-drive-system"
                name="gz::sim::systems::MecanumDrive">
            <update_rate>20</update_rate>
            <front_left_joint>your_front_left_wheel_joint_name</front_left_joint>
            <front_right_joint>your_front_right_wheel_joint_name</front_right_joint>
            <back_left_joint>your_back_left_wheel_joint_name</back_left_joint>
            <back_right_joint>your_back_right_wheel_joint_name</back_right_joint>
            <wheelbase>distance_between_front_and_back_wheel_in_meters</wheelbase>
            <wheel_separation>distance_between_left_and_right_wheel_in_meters</wheel_separation>
            <wheel_radius>radius_of_the_omni_wheel_in_meters</wheel_radius>
            <odom_publish_frequency>20</odom_publish_frequency>
            <topic>cmd_vel</topic>
            <odom_topic>odom</odom_topic>
            <tf_topic>tf</tf_topic>
            <frame_id>odom</frame_id>
            <child_frame_id>base_link or base_footprint<child_frame_id>
        </plugin>
    </gazebo>

Please try to understand documentations! It is very vital skill nowadays that people are often failing to cultivate given the rise of LLM systems which are basically making people more unskillful (in my opinion at least)!

Regards,
Girish

[ROxX]

Thank you, the plugin filename is what I have been looking for. When I look at the gazebo online references, it is very difficult to find the correct information for gazebo sim.

[ROxX]

I was able to use the file name you provided. But in the online
course the file name for diff steer is defined -
filename=“libignition-gazebo-diff-drive-system.so”
name=“ignition::gazebo::systems::DiffDrive”>
The online course is labeled Gazebo Sim, so I am confused as to why
the online course for diff steer does not have a gz format. Is there
a simple explanation?.
Thanks

[girishkumar.kannan]

Hi @ROxX ,

@ROxX

I was able to use the file name you provided. But in the online
course the file name for diff steer is defined -
filename=“libignition-gazebo-diff-drive-system.so”
name=“ignition::gazebo::systems::DiffDrive”>
The online course is labeled Gazebo Sim, so I am confused as to why
the online course for diff steer does not have a gz format. Is there
a simple explanation?.

That is because the course was created when Fortress was the current LTS version (at that time) and Garden was the next version. Fortress was branded as Ignition, but when Garden came out, the Gazebo developers re-branded “Ignition” back to “Gazebo”. But this time it was not called just “Gazebo”, but “Gazebo Sim”. It caused a lot of confusions (and is still causing confusion).
The course was created with Ignition Fortress but was deployed with Gazebo Garden version. This caused a whole new level of confusion.

Here is the plugin version re-worded for Ignition:

filename="libignition-gazebo-mecanum-drive-system.so"
name="ignition::gazebo::systems::MecanumDrive"

So if you look at the migration guide that I linked you to in my earlier post, you can understand how the plugin syntaxes are written on Ignition and Gazebo Sim.

I hope this clarifies your doubts!

Regards,
Girish

[ROxX]

Thank you, the sequence of development is surely complex. I appreciate the support you and others provide.

Regards,

Tom

[girishkumar.kannan]

Hi @ROxX ,

You’re welcome! I am glad I was able to help you out!

@ROxX

When I look at the gazebo online references, it is very difficult to find the correct information for gazebo sim.

Haha… it is quite a daunting task to go through Gazebo’s documentation pages. You can easily get lost within and go around in circles, linking you back to the same page you started with.

The Gazebo Sim course now offers a Certificate! If you have already completed the course, take up the course project and present your work on YouTube!

Cheers,
Girish