Add TF publishing in MecanumDrive system

[cccleon]

Thanks for your excellent work!
I use the mecanum plugin in my sdf file:
<plugin filename="ignition-gazebo-mecanum-drive-system" name="ignition::gazebo::systems::MecanumDrive"> <front_left_joint>front_left_wheel_joint</front_left_joint> <front_right_joint>front_right_wheel_joint</front_right_joint> <back_left_joint>rear_left_wheel_joint</back_left_joint> <back_right_joint>rear_right_wheel_joint</back_right_joint> <min_acceleration>-5</min_acceleration> <max_acceleration>5</max_acceleration> </plugin>
By running 'ign topic -l', I can see the topic "/model/xxx/odometry", but I get nothing when I echo this topic.
Additionally, "odom" frame is not in the TF tree, and there is no element like "publish_odom_tf" or "odom_frame" in MecanumDrive.cc, which can be found in the source code of navigation2 tutorial(diff-drive) .The tutorial uses 'libgazebo_ros_diff_drive.so', but I can't find the mecanum_drive.so

[chapulina]

Hi @cccleon , can you please update your feature request to follow the template?

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## Desired behavior
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## Alternatives considered
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## Implementation suggestion
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[andyblarblar]

It looks like the MecanumDrive system lacks an updateOdometry function unlike the ackermann and diffDrive systems. To get odom and TF you'll need to first calculate accurate odom for a Mec drive, and then copy that odom message exactly over to a Pose_V message for Tf. The publishers are in the mec drive file, but unused.

[cccleon]

It looks like the MecanumDrive system lacks an updateOdometry function unlike the ackermann and diffDrive systems. To get odom and TF you'll need to first calculate accurate odom for a Mec drive, and then copy that odom message exactly over to a Pose_V message for Tf. The publishers are in the mec drive file, but unused.

Thanks for your reply. You are right. The publisher is defined in line 308 but unused.

[cccleon]

Desired behavior

Add updateOdometry function in MecanumDrive.cc

Implementation suggestion

Caculate the odometry message from joint states and publish.

Additional context

Maybe users can specify the <robot_base_frame> and <odom_frame> in sdf, thus the plugin can publish the TF between odom frame and robot_base frame as they want.

Hi @cccleon , can you please update your feature request to follow the template?

<!-- If you're not sure on the specifics of the feature or would like a broader
discussion, please consider posting a proposal to
http://community.gazebosim.org/ instead.-->

## Desired behavior
<!-- Describe the current problem and the feature you want implemented.-->

## Alternatives considered
<!-- Describe alternate solutions or features you've considered.-->

## Implementation suggestion
<!-- Provide a suggestion on how to implement this feature, which could help us
expedite this implementation.-->

## Additional context
<!-- Provide any other additional context (e.g., screenshots) about your feature
request.-->

Thanks for your reply! I think the problem is the lack of updateOdometry function as @andyblarblar mentioned.

Desired behavior

Add updateOdometry function in MecanumDrive.cc

Implementation suggestion

Caculate the odometry message from joint states and publish.

Additional context

Maybe users can specify the <robot_base_frame> and <odom_frame> in sdf, thus the plugin can publish the TF between odom frame and robot_base frame as they want.

[danilogsch]

Hello everyone, I´ve been using this sim for some time now, awesome work by the way. I did 2 PRs to contribute on this issue:
#486
#1665

they are my first ones ever, please go easy on me. Does we need a TEST.cc?

[ahcorde]

Hi @danilogsch,

thank you for your contributions! I added some comments in the gz-math PR gazebosim/gz-math#486

Feel free to ask any question you have!

[danilogsch]

HI @ahcorde ,
I resolved most of it, on the gz-sim PR I am not able to rebase and sign off the commit, I am closing that to open a new one.