Fixed turning error in ackermann steering

[sauk2]

🦟 Bug fix

Fixes #2314

Summary

This is a fix to the error seen in Ackermann Steering's <steering_only> mode. The steps to reproduce this error are described in issue #2314.

The solution to this was changing signs in these equations.

Steps to check the fix

1. Add the following tag in the example SDF file of Ackermann Steering plugin.

  <steering_only>True</steering_only>

2. Build and source the workspace
3. Launch using the following command

  gz sim ackermann_steering.sdf

4. Publish the following

  gz topic -t "/model/vehicle_blue/steer_angle" -m gz.msgs.Double -p "data: 0.4"

Additionally comment out chassis visual for better visibility.

The output after fix looks like this

Checklist

• Signed all commits for DCO
• Added tests
• codecheck passed (See contributing)
• All tests passed (See test coverage)

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[bperseghetti]

Thanks @sauk2 when this gets merged do you want to close #2315 ?

[sauk2]

Thanks @sauk2 when this gets merged do you want to close #2315 ?

@bperseghetti Yes, I will go ahead and close #2315 once this gets merged. Thank you for your input and feedback on these PRs!