[Proposal] About including the Franka FR3 model in Orbit

[YZhang001]

Proposal

Hello, could you please include the Franka FR3 robot in orbit robot models? I read from the Isaac Sim 2023.1.1 release notes that it is now added. I'm asking because FR3 has different joint limits and maybe also other different specifications compared to the panda model.

And also from source/extensions/omni.isaac.orbit_assets/omni/isaac/orbit_assets/franka.py it seems there is only proportional term for joint velocity tracking using set_joint_velocity_target() function (stiffness for joint position and damping for joint velocity so it could be a PD-controller for joint position but only a P-controller for joint velocity). Is it possible to somehow extend the controller to a PD controller for joint velocity?

Motivation

I have tried to add the FR3 model myself with orbit, using the USD path usd_path=f"{ISAAC_NUCLEUS_DIR}/Robots/Franka/FR3/fr3.usd" and following the code structure from source/extensions/omni.isaac.orbit_assets/omni/isaac/orbit_assets/franka.py. But I don't know how to specify the joint position limits for it, and when I run my script there is always warnings about the model:

2024-05-24 13:24:50 [12,685ms] [Warning] [omni.physx.plugin] The rigid body at /World/envs/env_0/Robot/fr3_hand_tcp has a possibly invalid inertia tensor of {1.0, 1.0, 1.0} and a negative mass, small sphere approximated inertia was used. Either specify correct values in the mass properties, or add collider(s) to any shape(s) that you wish to automatically compute mass properties for.
2024-05-24 13:24:50 [12,685ms] [Warning] [omni.physx.plugin] The rigid body at /World/envs/env_0/Robot/fr3_link8 has a possibly invalid inertia tensor of {1.0, 1.0, 1.0} and a negative mass, small sphere approximated inertia was used. Either specify correct values in the mass properties, or add collider(s) to any shape(s) that you wish to automatically compute mass properties for.

I'm not sure whether this will affect the performance of joint velocity tracking and if there are other problems it might cause. If the FR3 model won't be included in orbit, what could I do to avoid these warnings?

Checklist

• [x] I have checked that there is no similar issue in the repo (required)

Acceptance Criteria

• [ ] Include Franka FR3 model into orbit assets
• [ ] PD-controller for joint velocity tracking with set_joint_velocity_target()