Custom URDF Vehicle Moving Backwards using ROS Differential Base

I am having an issue where the differential base setup using ROS in Isaac Sim cause my wheels to move backwards for a jeep-like vehicle. The back wheels are set to drive the system as well as steer but the issue has been bothering me for so long since i have no clue how to fix it. I have set my Axis to Y for all wheels and set them to use “Acceleration” in the Angular section. It also seems that my front wheels are stiff as a brick and make my vehicle jump up and down. I have included a video of the problem I’m facing. Is there a step I am missing to configure my vehicle?

I have attached a youtube link showing my issue:

I’m still having this issue.

I assume all of your wheel joints are under your base_link? In your front wheels’ joint setup, try checking the box “Exclude from Articulation” in the Property tab under the “Revolute Joint” section. Do the front wheels now spin freely when the jeep moves? If not, also try deleting the joint’s drive, so that there’s no actuation involved for those joints, only a mechanical connection.

The driving backwards may be related to a bug we are trying to fix.

how to get imported model to move at all? without ros ? is there a simple way to do so?

If you are writing scripts, dynamic control extension have examples on how to move the joints. If you just want to see if the joints could move or not, you can open the joint’s property and set a target velocity or target position under joint drive, and then press “play”.

In case of the jeep, you should be able to select the two rear wheel joints and set a target velocity and then press play (make sure those joints are have high damping and zero in stiffness for velocity control). Your front wheels should not even have a drive component since you shouldn’t technically be able to actuate it.