Robot wheels rotate but robot does not move

Hi I am having a slight issue, I believe there is probably something wrong with my USD file. So the USD I have was previously working with an older version of Isaac Sim but when I import it into Isaac 2021.1.0, a message informs me that the USD uses an out of date physics schema and I select the option to update it. I attempt to move the robot using an extension that is based on the navigation example, I can see that the wheels on the robot rotate but the robot does not move. I have attached the USD. Any ideas anyone?

robot_summit.usd (2.3 MB)


Hi Kirsty,

Please make sure you are using the latest Isaac Sim, 2021.1.1.
The physics schema has changed, but it should notify you and updated your USD file while loading.


Hi @ltorabi,

Thanks for your response, do you have any ideas of why I am seeing this issue? What could cause an issue where the wheels rotate but the robot does not move? When I import the USD I do not have any errors.


OK, so I managed to get it working. It seems that there was a joint that was fixing the robot in space - a remnant of Gazebo probably. I removed this and then the robot would fall through the floor - there seemed to be an issue with the floor, we were using the gridroom.usd from the sample code. I found that by replacing our copy of gridroom.usd with the version from the source code, the robot now sits on the floor and moves when I apply a drive to the wheels!

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glad you got it working :)