Quick Start: Move a Mobile Robot in NVIDIA Isaac Sim with Python

Title: Hello Robot — Isaac Sim Documentation

URL Source: https://docs.isaacsim.omniverse.nvidia.com/latest/core_api_tutorials/tutorial_core_hello_robot.html

Published Time: Tue, 21 Oct 2025 19:24:36 GMT

Markdown Content: Hello Robot#

Learning Objectives#

This tutorial details how to add and move a mobile robot in NVIDIA Isaac Sim in an extension application. After this tutorial, you will understand how to add a robot to the simulation and apply actions to its wheels using Python.

10-15 Minute Tutorial

Getting Started#

Prerequisites

Review Hello World prior to beginning this tutorial.

Begin with the source code of the Awesome Example developed in the previous tutorial: Hello World.

Adding a Robot#

Begin by adding a NVIDIA Jetbot to the scene, which allows you to access the library of NVIDIA Isaac Sim robots, sensors, and environments located on a Omniverse Nucleus Server using Python, as well as navigate through it using the Content window.

Note

The server shown in these steps has been connected to in Workstation Setup. Follow these steps first before proceeding.

Add the assets by simply dragging them to the stage window or the viewport.
Try to do the same thing through Python in the Awesome Example.
Create a new stage: File > new > Don’t Save
Open the extension_examples/user_examples/hello_world.py file by clicking the Open Source Code button in the Awesome Example window.

1from isaacsim.examples.interactive.base_sample import BaseSample 2 from isaacsim.core.utils.nucleus import get_assets_root_path 3 from isaacsim.core.utils.stage import add_reference_to_stage 4 from isaacsim.core.api.robots import Robot 5import carb 6 7 8class HelloWorld(BaseSample): 9 def init (self) -> None: 10 super(). init () 11 return 12 13 def setup_scene(self): 14 world = self.get_world() 15 world.scene.add_default_ground_plane() 16 # you configure a new server with /Isaac folder in it17 assets_root_path = get_assets_root_path()18 if assets_root_path is None: 19 # Use carb to log warnings, errors, and infos in your application (shown on terminal) 20 carb.log_error("Could not find nucleus server with /Isaac folder") 21 asset_path = assets_root_path + "/Isaac/Robots/NVIDIA/Jetbot/jetbot.usd" 22 # This will create a new XFormPrim and point it to the USD file as a reference 23 # Similar to how pointers work in memory 24 add_reference_to_stage(usd_path=asset_path, prim_path="/World/Fancy_Robot") 25 # Wrap the jetbot prim root under a Robot class and add it to the Scene26 # to use high level api to set/ get attributes as well as initializing 27 # physics handles needed..etc. 28 # Note: this call doesn't create the Jetbot in the stage window, it was already 29 # created with the add_reference_to_stage30 jetbot_robot = world.scene.add(Robot(prim_path="/World/Fancy_Robot", name="fancy_robot"))31 # Note: before a reset is called, we can't access information related to an Articulation32 # because physics handles are not initialized yet. setup_post_load is called after 33 # the first reset so we can do so there 34 print("Num of degrees of freedom before first reset: " + str(jetbot_robot.num_dof)) # prints None 35 return 36 37 async def setup_post_load(self): 38 self._world = self.get_world() 39 self._jetbot = self._world.scene.get_object("fancy_robot") 40 # Print info about the jetbot after the first reset is called 41 print("Num of degrees of freedom after first reset: " + str(self._jetbot.num_dof)) # prints 242 print("Joint Positions after first reset: " + str(self._jetbot.get_joint_positions()))43 return

Press the PLAY button to start simulating the robot. Although it is being simulated, it is not moving. The next section walks through how to make the robot move.

Move the Robot#

In NVIDIA Isaac Sim, Robots are constructed of physically accurate articulated joints. Applying actions to these articulations make them move.

Next, apply random velocities to the Jetbot articulation controller to get it moving.

1from isaacsim.examples.interactive.base_sample import BaseSample 2 from isaacsim.core.utils.types import ArticulationAction 3from isaacsim.core.utils.nucleus import get_assets_root_path 4from isaacsim.core.utils.stage import add_reference_to_stage 5from isaacsim.core.api.robots import Robot 6import numpy as np 7import carb 8 9 10class HelloWorld(BaseSample): 11 def init (self) -> None: 12 super(). init () 13 return 14 15 def setup_scene(self): 16 world = self.get_world() 17 world.scene.add_default_ground_plane() 18 assets_root_path = get_assets_root_path() 19 if assets_root_path is None: 20 carb.log_error("Could not find nucleus server with /Isaac folder") 21 asset_path = assets_root_path + "/Isaac/Robots/NVIDIA/Jetbot/jetbot.usd" 22 add_reference_to_stage(usd_path=asset_path, prim_path="/World/Fancy_Robot") 23 jetbot_robot = world.scene.add(Robot(prim_path="/World/Fancy_Robot", name="fancy_robot")) 24 return 25 26 async def setup_post_load(self): 27 self._world = self.get_world() 28 self._jetbot = self._world.scene.get_object("fancy_robot") 29 # This is an implicit PD controller of the jetbot/ articulation30 # setting PD gains, applying actions, switching control modes..etc.31 # can be done through this controller.32 # Note: should be only called after the first reset happens to the world33 self._jetbot_articulation_controller = self._jetbot.get_articulation_controller()34 # Adding a physics callback to send the actions to apply actions with every35 # physics step executed.36 self._world.add_physics_callback("sending_actions", callback_fn=self.send_robot_actions)37 return 38 39 def send_robot_actions(self, step_size): 40 # Every articulation controller has apply_action method 41 # which takes in ArticulationAction with joint_positions, joint_efforts and joint_velocities 42 # as optional args. It accepts numpy arrays of floats OR lists of floats and None 43 # None means that nothing is applied to this dof index in this step 44 # ALTERNATIVELY, same method is called from self._jetbot.apply_action(...) 45 self._jetbot_articulation_controller.apply_action(ArticulationAction(joint_positions=None,46 joint_efforts=None,47 joint_velocities=5 * np.random.rand(2,)))48 return

Press the PLAY button to start simulating the robot.

Note

Pressing STOP, then PLAY in this workflow might not reset the world properly. Use the RESET button instead.

Using the WheeledRobot Class#

NVIDIA Isaac Sim also has robot-specific extensions that provide further customized functions and access to other controllers and tasks (more on this later). Now you’ll re-write the previous code using the WheeledRobot class to make it simpler.

1from isaacsim.examples.interactive.base_sample import BaseSample 2from isaacsim.core.utils.nucleus import get_assets_root_path 3 from isaacsim.robot.wheeled_robots.robots import WheeledRobot 4from isaacsim.core.utils.types import ArticulationAction 5import numpy as np 6 7 8class HelloWorld(BaseSample): 9 def init (self) -> None: 10 super(). init () 11 return 12 13 def setup_scene(self): 14 world = self.get_world() 15 world.scene.add_default_ground_plane() 16 assets_root_path = get_assets_root_path()17 jetbot_asset_path = assets_root_path + "/Isaac/Robots/NVIDIA/Jetbot/jetbot.usd"18 self._jetbot = world.scene.add(19 WheeledRobot(20 prim_path="/World/Fancy_Robot",21 name="fancy_robot",22 wheel_dof_names=["left_wheel_joint", "right_wheel_joint"],23 create_robot=True,24 usd_path=jetbot_asset_path,25 )26 )27 return 28 29 async def setup_post_load(self): 30 self._world = self.get_world() 31 self._jetbot = self._world.scene.get_object("fancy_robot") 32 self._world.add_physics_callback("sending_actions", callback_fn=self.send_robot_actions) 33 return 34 35 def send_robot_actions(self, step_size): 36 self._jetbot.apply_wheel_actions(ArticulationAction(joint_positions=None,37 joint_efforts=None,38 joint_velocities=5 * np.random.rand(2,)))39 return

Summary#

This tutorial covered the following topics:

Adding NVIDIA Isaac Sim library components from a Nucleus Server
Adding a Robot to the World
Using a joint-level controller to articulate a Robot
Using Robot classes
Using Robot specific extensions

Next Steps#

Continue on to the next tutorial in the Essential Tutorials series, Adding a Controller, to learn how to add a controller to Jetbot.

Further Learning#

Nucleus Server

For an overview of how to best leverage a Nucleus Server, see the Nucleus Overview in NVIDIA Omniverse tutorial.

Robot Specific Extensions

NVIDIA Isaac Sim provides several robot extensions such as isaacsim.robot.manipulators.examples.franka, isaacsim.robot.manipulators.examples.universal_robots, and many more. To learn more, check out the standalone examples located at standalone_examples/api/isaacsim.robot.manipulators/franka and standalone_examples/api/isaacsim.robot.manipulators/universal_robots/.

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