[Question] import ur10e_robotiq2f-140.usd correctly

[dzy666fly]

Thank us so much for developing this wonderful simulator! Now I find the error, which I search related issues both in the document, github issue pages and forum but do not find useful info; although in the document the manipulated environment is mentioned, but tutorials of robotiq gripper, which is widely used, is missing.

When I try to use UR10e and robotiq gripper with the official USD file (Isaacsim_assets/Assets/Isaac/4.5/Isaac/Robots/UR10/ur10e_robotiq2f-140.usd), the error shows as follows:
2025-07-31 13:22:47 [23,712ms] [Error] [omni.physx.plugin] PhysX error: PxArticulationJointReducedCoordinate::setDriveTarget(): it is illegal to call this method if PxSceneFlag::eENABLE_DIRECT_GPU_API is enabled!, FILE /builds/omniverse/physics/physx/source/physx/src/NpArticulationJointReducedCoordinate.cpp, LINE 304
Well, if we use CPU, it will show another error:
2025-07-31 13:02:25 [24,759ms] [Error] [omni.physx.plugin] PhysX error: Illegal BroadPhaseUpdateData , FILE /builds/omniverse/physics/physx/source/lowlevelaabb/src/BpBroadPhaseABP.cpp, LINE 4023

I notice that the damping and stiffness parameters of the gripper USD is close to 0, which seem not to be reasonable. But even the damping is set to 100 and stiffness with 2000, it still shows error. So how should I import ur10e_robotiq2f-140.usd correctly?

Here is the related code.

UR10_CFG = ArticulationCfg(
        prim_path="{ENV_REGEX_NS}/mounter/ur10",
        spawn=sim_utils.UsdFileCfg(
            usd_path=local_base_path + "Robots/UR10/ur10e_robotiq2f-140.usd",
            rigid_props=sim_utils.RigidBodyPropertiesCfg(
                disable_gravity=False,
                max_depenetration_velocity=5.0,
            ),
            activate_contact_sensors=False,
        ),
        init_state=ArticulationCfg.InitialStateCfg(
            joint_pos={
                "shoulder_pan_joint": radians(-27.3),
                "shoulder_lift_joint": radians(-65.8),
                "elbow_joint": radians(105.8),
                "wrist_1_joint": radians(262.1),
                "wrist_2_joint": radians(143.57),
                "wrist_3_joint": radians(129.2),
                'right_inner_finger_pad_joint': 0.0,
                'left_inner_finger_pad_joint': 0.0,
            },
            pos=(0.54, -0.24, 1.444),
            rot=(0., 0.0, 0.866, 0.5),
        ),
        actuators={
            "arm": ImplicitActuatorCfg(
                joint_names_expr=[
                    "shoulder_pan_joint",
                    "shoulder_lift_joint",
                    "elbow_joint",
                    "wrist_1_joint",
                    "wrist_2_joint",
                    "wrist_3_joint", ],
                velocity_limit_sim=100.0,
                effort_limit_sim=87.0,
                damping=34.9,
                stiffness=349.0,
            ),
            "gripper": ImplicitActuatorCfg(
                joint_names_expr=[
                    'finger_joint',
                    'right_outer_knuckle_joint',
                    'left_outer_finger_joint',
                    'right_outer_finger_joint',
                    'left_inner_finger_joint',
                    'right_inner_finger_joint',
                    'left_inner_finger_pad_joint',
                    'right_inner_finger_pad_joint'],
                effort_limit_sim=200.0,
                velocity_limit_sim=0.2,
                stiffness=2e3,
                damping=1e2,
            ),
        },
    )
    # articulation
    robot = UR10_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")


def run_simulator(sim: sim_utils.SimulationContext, scene: InteractiveScene):
    """Runs the simulation loop."""
    robot = scene["robot"]

    # Define simulation stepping
    sim_dt = sim.get_physics_dt()
    count = 0

    root_state = robot.data.default_root_state.clone()
    robot.write_root_pose_to_sim(root_state[:, :7])
    robot.write_root_velocity_to_sim(root_state[:, 7:])
    # set joint positions
    joint_pos, joint_vel = robot.data.default_joint_pos.clone(), robot.data.default_joint_vel.clone()
    print(root_state)
    print(joint_pos)
    robot.write_joint_state_to_sim(joint_pos, joint_vel)

    while simulation_app.is_running():
        # root_state = robot.data.default_root_state.clone()
        print('------------*', count, '*------------')
        print(robot.data.joint_pos)
        sim.step()
        count += 1
        # # Update buffers
        robot.update(sim_dt)

Lastly, here is the used version and info.
IsaacLab version: 4.5.0
System: Ubuntu 22.04.5 LTS
Nvidia Driver Version: 575.64.03
GPU: Nvidia RTX 3090

Looking forward to ur reply.
Sincerely.

[RandomOakForest]

Thank you for posting this. Here is a summary to consider, still under review, though.

1. Understand the Errors:

• PxArticulationJointReducedCoordinate::setDriveTarget error (in GPU mode):
  This error means the simulation tries to use a method (drive targets for joints) unsupported when the PxSceneFlag::eENABLE_DIRECT_GPU_API flag is enabled. It is commonly triggered by trying to directly apply joint targets in environments configured for GPU PhysX.
• Illegal BroadPhaseUpdateData error (in CPU mode):
  Indicates simulation instability, often from invalid or NaN transforms/physics parameters on bodies or joints¹²³.

2. Workflow to Combine UR10e and Robotiq 2F-140:

Use the official assets and the latest Isaac Sim features:

A. Assemble the Robot and Gripper Under a Single Articulation

• Do NOT use multiple separate Articulation Roots; the robot and gripper must be under one articulation for stable physics and simulation.
• Remove any additional "Articulation Root" from the gripper after importing it and attach it directly to the robot’s correct link.

B. Properly Set and Tune Physics/Drive Parameters

Tuning joint parameters is essential for stability—especially for industrial robots and grippers:

1. Increase Solver Iterations for Better Stability:
   • Set Solver Position Iterations Count to 64.
   • Set Solver Velocity Iterations Count to 4
     These are available in the Physics/Articulation section of the robot’s root joint⁴.
2. Set Reasonable Damping and Stiffness for Gripper:
   According to NVIDIA docs, after conversion/import:
   • For the main finger joint:
     • Stiffness: ~0.26
     • Damping: ~0.0001
     • Max Force: 1000
   • For mimic joints, use higher natural frequency (2500), and a small damping ratio (0.005).
   • These match the expected import parameters in official Robotiq+UR10e workflows⁵.
3. Set Physical Material Properties (For the Gripper):
   • Set static friction and dynamic friction to 1.0 on the gripper’s contact surfaces.
   • Apply physics material to all important end-effector contact points⁴.

C. Set Sleep and Stabilization Thresholds (For Articulation Stability):

• Sleep Threshold: 0.00005
• Stabilization Threshold: 0.00001
  These reduce erratic movement and help prevent simulation instability⁴.

3. Recommended Import Process

• Import the base UR10e and Robotiq 2F-140 USD assets separately, following the [docs and manipulation tutorials]⁵⁴.
• Assemble them as a single articulation, then set the above simulation parameters using Isaac Sim’s GUI:
  • Set joint drive values and physics material from the Property Editor.
  • Use the Physics Inspector and Gain Tuner tools for calibration.
• Always save the completed, configured assembly as a new USD file for stable re-use.

Footnotes

1. https://forums.developer.nvidia.com/t/illegal-broadphaseupdatedata/243041 ↩

2. https://forums.developer.nvidia.com/t/physx-error-illegal-broadphaseupdatedata/275325 ↩

3. https://github.com/NVIDIA-Omniverse/Orbit/issues/161 ↩

4. https://docs.isaacsim.omniverse.nvidia.com/latest/robot_setup_tutorials/tutorial_configure_manipulator.html ↩ ↩² ↩³ ↩⁴

5. https://docs.isaacsim.omniverse.nvidia.com/latest/robot_setup_tutorials/tutorial_import_assemble_manipulator.html ↩ ↩²

[dzy666fly]

Thank u so much for timely reply.

Before assembling UR10e and Robotiq USD assets, I try to follow the document u mentioned https://docs.isaacsim.omniverse.nvidia.com/latest/robot_setup_tutorials/tutorial_import_assemble_manipulator.html to generate a USD asset of gripper from the URDF file.
However, after reading the USD asset of gripper in the Isaac Sim GUI, it still shows error as follows when I try to use Physics Inspector to change the position of finger joint.
[604,695ms] [Error] [omni.physx.plugin] PhysX error: PxArticulationJointReducedCoordinate::setDriveTarget(): it is illegal to call this method if PxSceneFlag::eENABLE_DIRECT_GPU_API is enabled!, FILE /builds/omniverse/physics/physx/source/physx/src/NpArticulationJointReducedCoordinate.cpp, LINE 304
So how I solve this problem?

By the way, I notice that in the tutorial it says some related USD assets such as Isaac Sim/Samples/Rigging/Manipulator/import_manipulator/ur10e/ur/ur_gripper_manual.usd, how can I download it? I guess maybe these assets will be released in the future haha.

Looking forward to ur rely.
Sincerely

[RandomOakForest]

Thank you for following up. You may want to try the latest versions of the tools. Follow #3021 to update. I'll move this post to our Discussions to follow up.