Planet ROS
Planet ROS - http://planet.ros.org
Planet ROS - http://planet.ros.org
http://planet.ros.org
ROS Discourse General: Plotjuggler 4 (beta!) is here. Unleashing mulit-modal data
After few months of hard work, PlotJuggler 4 is finally ready for an early preview!
Expect bugs and missing features, but also ton of awesomeness unleashed.
Everything was brutally optimized. Playing a compressed MCAP, reading lazily the file from disk, and rendering 3 videos and the two 3D scenes above, for a total of 6 pointclouds, uses only 50% of a single CPU core.
Features: too many to list
- 2D: images, compressed images, depth, compressed video (H264, AV1).
- 2D: image rectification!
- 2D: real-time streaming with WebRTC!
- 2D: markers!
- 3D: meshes, occupancygrid, TF2, 3D markers
- 3D: pointclouds, including compressed ones (Draco and Cloudini)
- 3D: multiple cameras control, similar to RViz
On the “core” side
- Refactor data engine that will use up to 5x less memory when loading large datasets.
- To be opened soon: a marketplace of “Extensions” (think VSCode equivalent) to share plugins with others.
- a new parallel MCAP loader that can load compressed MCAPs about 4X faster.
And (this is big) integration with Mosaico to access directly data stored in the cloud.
4 posts - 3 participants
ROS Discourse General: Mastering NERO | How to Configure CAN Leader–Follower Linkage for Dual 7-DoF Robotic Arms
Dual-arm robots are becoming increasingly important in embodied AI, teleoperation, imitation learning, and collaborative manipulation research.
This tutorial demonstrates how to configure two AgileX NERO 7-DOF robotic arms in a leader-follower setup using CAN bus communication. Once configured, the follower arm will automatically replicate the motion of the leader arm in real time.
What You’ll Build
By the end of this guide, you’ll be able to:
Synchronize two NERO robot arms
Enable real-time leader-follower motion following
Configure CAN-based dual-arm communication
Validate coordinated dual-arm operation
Prepare a platform for teleoperation and imitation learning experiments
Hardware Requirements
| Component | Quantity |
|---|---|
| NERO 7-DOF Robotic Arm (Leader) | 1 |
| NERO 7-DOF Robotic Arm (Follower) | 1 |
| CAN Communication Cable | 1 |
| NERO Control Software | 1 |
Step 1: Connect the CAN Bus
The first step is connecting the CAN communication lines between the two robot arms.
Wiring Rules
| Wire Color | Signal |
|---|---|
| Yellow | CAN H |
| Blue | CAN L |
Connect:
-
CAN H ↔ CAN H
-
CAN L ↔ CAN L
Important
Before powering on:
-
Verify all connectors are secure.
-
Ensure there are no loose contacts.
-
Check that CAN H and CAN L are not reversed.
Incorrect wiring may prevent communication between the two robotic arms.
Step 2: Configure Leader and Follower Modes
Once the CAN bus connection is complete, assign the role of each robot arm.
Leader Arm
The leader arm acts as the command source.
Responsibilities:
-
Generates motion commands
-
Broadcasts joint states
-
Controls overall synchronization
Follower Arm
The follower arm executes the motion commanded by the leader arm.
Responsibilities:
-
Receives leader motion data
-
Replicates joint trajectories
-
Mirrors the leader’s pose in real time
After configuration, save all parameters before proceeding.
Safety Warning Before Activation
Read This Before Enabling Leader-Follower Mode
Before assigning leader-follower roles:
- Move both robotic arms close to their home positions.
- Ensure the workspace is clear.
- Remove any obstacles around the robot.
When synchronization is activated, the follower arm immediately attempts to match the leader’s current pose.
If the initial poses differ significantly, the follower arm may move rapidly, potentially causing:
-
Robot collisions
-
Pinch hazards
-
Hardware damage
-
Personal injury
For safe operation, always align both robots before enabling synchronization.
Step 3: Validate Leader-Follower Synchronization
After configuration, verify that communication and synchronization are functioning correctly.
Validation Procedure
- Check CAN Connections
Verify:
-
CAN H is connected correctly
-
CAN L is connected correctly
-
No loose cables exist
- Verify Control Modes
Confirm:
- Leader mode is enabled
- Follower mode is enabled
- Parameters have been saved successfully
- Move the Leader Arm
Manually operate the leader arm.
- Observe the Leader Arm
The Leader arm should:
- Follow every joint movement
- Replicate end-effector trajectories
- Maintain smooth synchronized motion
Successful tracking indicates that Leader-Follower control is operating correctly.
Software Version Notes
Version 1.1 API Limitation
For NERO software version 1.1:
When Leader-Follower mode is enabled:
- API access is limited to commands issued by the leader arm.
- Independent follower-arm state information cannot be queried separately.
Developers building custom applications should account for this behavior when logging data or implementing monitoring systems.
Conclusion
Using a simple CAN bus connection, two NERO 7-DOF robotic arms can be configured into a synchronized leader-follower system capable of real-time trajectory replication and coordinated motion control.
This setup is particularly useful for:
- Embodied AI development
- Teleoperation platforms
- Imitation learning pipelines
- Robot data collection
- Research and education
By following the wiring, configuration, and safety recommendations in this guide, developers can quickly deploy a reliable dual-arm robotic platform for experimentation and application development.
FAQ

Q1:Why does the follower arm move suddenly when leader-follower mode is enabled?
When leader-follower mode is activated, the follower arm immediately attempts to match the current pose of the leader arm.
If the two arms start from significantly different positions, the follower arm may perform a rapid corrective movement.
Q2:The follower arm is not following the leader arm. What should I check first?
Verify the following items:
- CAN H and CAN L are connected correctly.
- Leader and follower modes are configured properly.
- Configuration settings have been saved.
- The CAN cable is firmly connected.
- Both robot arms are running compatible software versions.
In most cases, incorrect CAN wiring or unsaved configuration parameters are the root causes.
Q3:Why does the follower arm stop responding after working correctly for a period of time?
This behavior is typically caused by:
- Loose CAN connectors
- Unstable power supply
- CAN bus communication interruptions
- Software configuration changes
Check cable integrity, power stability, and communication status before restarting the system.
Q4:What should I do if the follower arm’s motion does not exactly match the leader arm?
Check the following:
- Joint calibration status
- Home position accuracy
- Mechanical interference
- Firmware version consistency
- CAN communication quality
Small tracking errors can often be reduced by recalibrating both robot arms and ensuring they start from similar initial poses.
Have Question?
If you encounter any issues with environment installation, parameter configuration, or RL training, feel free to leave your questions for further discussion.
3 posts - 2 participants
ROS Industrial: ros2_canopen: Natively Integrating CANopen Devices into the ROS 2 Ecosystem
CANopen has long been one of the most widely used communication standards in industrial automation. Built on top of the CAN bus and standardised by CAN in Automation (CiA), it connects motor drives, I/O modules, sensors and other field devices across machines, robots and vehicles. The ros2_canopen stack, maintained under the ROS-Industrial umbrella, brings this ecosystem natively into ROS 2. It lets developers describe a CAN bus, bring up a CANopen master, and talk to every device on the bus through standard ROS 2 nodes, services, topics and ros2_control interfaces.
Built on the lely-core from Lely Industries N.V.
Rather than reimplementing the CANopen protocol, ros2_canopen builds on lely-core, the professional, open-source CANopen library from Lely Industries N.V. lely-core handles the demanding low-level work: the CANopen event loop, NMT state management, SDO and PDO communication, and a configuration toolchain that turns a human-readable bus description into the device configuration files (DCF) the master needs at runtime.
Basic capability
At the heart of the stack is a device container that reads a single YAML bus description. In that file you declare each node on the bus (its node ID, its EDS file, and the driver to load for it) together with any parameters that override the device defaults. From that one description, the container launches the CANopen master and the per-device drivers.
To accommodate a wide range of industrial use cases, ros2_canopen offers three flexible operation modes depending on your application's requirements:
- Standard ROS2 Nodes: Best for simple setups. Each CANopen device is run as a standard ROS2 node, communicating through basic topics and services.
- Managed Lifecycle Nodes: Adds system reliability and recovery. Devices are wrapped as lifecycle nodes, allowing a manager to bring the entire CAN bus online or offline in a precise, safe sequence.
ros2_controlIntegration: Built for high-performance and low-latency control. This mode exposes CANopen devices directly as hardware interfaces for the broader ROS 2 control framework.
To interface with your hardware, the stack provides two primary drivers out of the box:
- The Proxy Driver: A generic bridge that forwards raw CANopen messages (such as SDOs and PDOs) to and from ROS 2. It is perfect for custom sensors, debugging, or devices without a standardized profile.
- The CiA 402 Driver: A specialized motion-control driver that implements the industry-standard profile for motor drives and servo controllers, allowing you to command positions, velocities, and torques natively.
New feature: Multi-drive systems
Multi-drive coordination has become a particular focus of the project's recent development. The stack has always been able to run several drives on a single bus, each as its own CANopen node sharing one master, with the CiA 402 driver providing the full motion-control profile: control and status words, profiled and cyclic position, velocity and torque modes, and interpolated position mode. Every node is configured independently in the bus description, with its own PDO mappings and unit-scaling factors.
The most recent releases added CiA 402 multi-channel support, which lets a single CANopen node expose more than one drive axis. Many modern servo controllers pack two or more axes behind a single node, and the driver now maps each axis to its own channel, with its own state machine and operation mode, so each can be commanded individually. Together with the existing multi-node setup, the stack now covers both ways of building a multi-drive system.
Behind the scenes, the CANopen master automatically coordinates all communication. It manages the flow of commands so you can control multiple motor axes simultaneously without worrying about network conflicts. It also keeps the motors perfectly synchronized, which is essential when multiple joints must move in harmony.
On the ROS 2 side, the stack groups these individual drives together and presents them to the system as a single, unified robot. Each motor axis is mapped directly to a standard robot joint. As a result, you can control your entire multi-axis machine using familiar ROS 2 controllers and visualize its movement in RViz just like any other robot.
Acknowledgments
the ros2_canopen stack provides a robust, modern, and highly flexible framework for integrating industrial CANopen devices into the ROS2 ecosystem. By leveraging a reliable open-source CANopen engine and integrating tightly with ros2_control, it lowers the barrier to building and controlling complex multi-drive robot systems.
This progress is a true community effort. A huge thank you goes to all the contributing developers and partner organizations whose dedication has shaped the core architecture, hardware interface capabilities, and testing infrastructure. We are particularly grateful for the community-contributed CiA 402 multi-channel support, which has made orchestrating multi-axis drives easier than ever.
To explore the codebase, report issues, or contribute to the project, check out the official https://github.com/ros-industrial/ros2_canopen
ROS Discourse General: Offboard Control with PX4 & ROS 2 (Micro XRCE-DDS)
I wanted to share an architectural pattern for handling autonomous drone navigation using ROS 2 (Jazzy) and PX4 Autopilot via Micro XRCE-DDS, specifically regarding the Offboard mode failsafe.
The Problem: When developing an autonomous flight node in C++, transitioning to PX4’s Offboard mode can be tricky. PX4 implements a strict failsafe: it will reject any VEHICLE_CMD_DO_SET_MODE to Offboard unless it detects a continuous stream of setpoints (e.g., TrajectorySetpoint and OffboardControlMode) at >2Hz prior to the request.
A common beginner mistake is using while loops with std::this_thread::sleep_for() to pre-load these setpoints. This is an anti-pattern in ROS 2 because it blocks the executor’s thread, preventing the node from processing incoming telemetry from the drone.
The Solution: Instead of blocking the thread, we implemented a non-blocking State Machine driven by the ROS 2 Executor using rclcpp::Node::create_wall_timer.
By setting a timer to fire exactly every 50ms (20Hz), we delegate the time-keeping to the Executor. Inside the timer’s single callback, we manage a state machine that handles the initialization sequence safely:
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Pre-flight Heartbeat: The callback counts up to 20 cycles (1 second) publishing dummy setpoints to satisfy the PX4 failsafe.
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Mode Switch: On the 21st cycle, it publishes the Offboard command.
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Arming: It sends the Arm command.
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Mission Loop: It continues publishing the actual trajectory setpoints at 20Hz without ever blocking the main thread.
Resources: rclcpp: rclcpp::node::Node Class Reference , Offboard Mode | PX4 User Guide , Create wall timer using callback with parameters.
1 post - 1 participant
ROS Discourse General: Pyspacemouse axis conventions
Thanks to new contributor, we have documentation of, and several options for, axis conventions in pyspacemouse
not yet released to pypi, but please try it out (you can pip install directly from github!) and let me know what you think.
Longer term, the plan is to change the default convention to HID, because the LEGACY convention is, frankly, insane, and I don’t want all users to have to “fix it” on their own.
1 post - 1 participant
ROS Discourse General: Guidelines for AI-Assisted Contributions in the ROS Project
Hello fellow ROS users, maintainers, contributors and anyone else who may be passing by.
Due to a recent uptick in LLM-authored pull requests, the ROS PMC has elected to extend the upstream OSRF policy on the use of generative tools to help provide some boundaries/guidelines on the use of these tools. These tools and technologies are constantly changing, so this isn’t intended to serve as a permanent policy, but rather it is to provide a framework for how to interact on ROS-related projects.
The TLDR, because there are a lot of words below: Feel free to use the tools to build, explore, and understand software (as many of the maintainers also do), but when it comes time to interact on Discourse, Zulip, or Github, try to leave the LLM-centric text behind. A large component of open source software is about building/collaborating with people, and we would generally prefer to interact with people rather than an LLM-proxy.
Maintainer time is a finite and constrained resource. While generative AI tools can be useful development assistants, submitting unverified Large Language Model (LLM) output shifts the engineering, debugging, and verification work onto project maintainers.
This document establishes the rules for interacting with ROS project repositories when using AI tools. It serves as an extension of the upstream OSRF Policy on the Use of Generative Tools in Contributions. While the upstream policy defines the legal, IP, and attribution requirements for AI-generated code, these rules define the quality and behavioral standards required to protect maintainer bandwidth.
The Author Ownership Rule
The upstream OSRF policy states that contributors must have the right to sign the Developer Certificate of Origin (DCO). Operationally, this means you are the sole owner of, and are fully responsible for, the code you submit.
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Do not use maintainers as an LLM validation service. If a maintainer points out a bug, architectural issue, or syntax error in your PR, you may not simply paste that feedback back into an LLM and copy-paste the unverified output as a response.
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You must understand every line of code you submit. If a maintainer asks why a specific technical choice was made, responding with “an LLM generated this” or providing a generic, AI-synthesized explanation is unacceptable. You must be able to defend the technical merits of your implementation yourself.
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Maintainers want to engage with you, the author of the proposed changes. Maintainers want to understand why you want to make the change and why you want to implement it the way the PR proposes. Maintainers do not want to talk to your chatbot.
Zero-Tolerance for Hallucinated API/Dependency Usage
LLMs frequently hallucinate APIs, configuration parameters, or entire library features, especially given the fast-moving nature of ROS releases and underlying middleware (DDS, Zenoh, rclcpp, rclpy, etc.).
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Any PR that introduces non-existent APIs, impossible configuration keys, or broken logic due to LLM hallucinations will be closed immediately without review.
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Repeat offenses will result in a temporary or permanent block from the organization’s repositories.
Compliance with Upstream Disclosure & Attribution
The upstream OSRF policy explicitly requires that the use of generative tools be disclosed if they created a material part of the contribution. We enforce this strictly on GitHub:
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If an LLM was used to generate structural code, tests, or documentation boilerplate, state it clearly in the PR description.
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Do not LLM dump to generate your PR description. Paragraphs filled with generic AI phrasing (e.g., “This PR enhances the efficiency of the codebase by utilizing modern design patterns and optimizing asynchronous paradigms…”) will be rejected. Write a concise, human-authored summary explaining exactly what changed and why.
Enforcement and Maintainer Recourse
To maintain the health of the project, maintainers have full discretion to handle low-effort, AI-driven contributions efficiently:
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If an issue or PR is clearly an unverified LLM dump (e.g., containing generic AI comments, formatting that violates project style guides, contains a poorly formatted description pasted directly from an LLM, or obviously broken logic), maintainers are authorized to close the PR immediately.
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If a contributor responds to code review feedback using obvious, unedited LLM-generated text that fails to address the underlying engineering critique, maintainers are authorized to close the PR immediately.
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If the contributor fails to respond to reviewer questions or feedback within a reasonable timeframe (e.g. within a week), reviewers may close the PR without further review.
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If a contributor continues to behave in an unproductive way through repeated submission of inappropriate LLM-dump issues or PRs, repeated copy-and-pasting of LLM-dump comments, or similar, maintainers are authorized to temporarily or permanently block that user from the organization’s repositories.
Guidelines for Responsible AI Use in ROS
If you want to use an LLM to help you successfully contribute to ROS, adhere to the following workflow:
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Confirm that the issue is still valid and that any proposed solution is still preferred. Start a conversation on the issue thread to ensure maintainers agree with the approach. Opening PRs for stale or invalid issues simply because an AI bot identified them creates unnecessary overhead for maintainers and is strongly discouraged.
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Run the code locally. Verify it compiles, passes linting, and passes all relevant tests before opening a PR.
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Before hitting “Submit,” read through your own diff line-by-line. Remove any redundant logic, overly verbose AI-generated comments, or structural weirdness introduced by the model.
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Explain your changes in plain technical language. If you can’t describe the change yourself, you aren’t ready to submit it.
12 posts - 8 participants
ROS Discourse General: Logging and Observability Guide Review | Cloud Robotics WG Meeting 2026-07-13
The group is not meeting today (2026-06-29) due to lack of available members!
Please come and join us for this coming meeting at Mon, Jul 13, 2026 4:00 PM UTC→Mon, Jul 13, 2026 5:00 PM UTC, where we will be editing the first draft of the Logging and Observability guide, generated by AI. The AI used the skeleton of the guide from the previous session and transcripts from all meeting recordings to generate a guide. The group will edit this starting point together in the coming session.
Please note: as this session will be a lot of reading and editing, the group does not plan to record the session.
Last session, we created the skeleton for the guide above, as we have been discussing Logging and Observability tips and best practices over the course of several months. Once the guide has been fully written, previous guest speakers will be invited to review it before it’s published. If you’re interested in watching the previous session, the meeting recording is available on YouTube.
The meeting link for next meeting is here, and you can sign up to our calendar or our Google Group for meeting notifications or keep an eye on the Cloud Robotics Hub.
Hopefully we will see you there!
1 post - 1 participant
ROS Discourse General: A Standard Interface from LLM to Robot Actions
Hi ROS community,
I’m working on ClawsJoy Robotics, a proposal for a standard interface between LLM-based cognitive systems and ROS/2 robots. The core idea: any LLM outputs an action, any robot implements these standard topics.
The Problem
Every robotics company maps “pick up the cup” to different ROS/2 interfaces:
-
Company A: custom service
/manipulation/pick -
Company B: action server
/grasp_object -
Company C: proprietary SDK
There’s no standard way for an LLM agent to tell a robot what to do.
The Proposal: 12 Standard Motion Primitives
navigate_to → /base/cmd_vel (geometry_msgs/Twist)
move_arm → /arm/joint_trajectory (trajectory_msgs/JointTrajectory)
move_base → /base/cmd_vel (geometry_msgs/Twist)
grasp → /gripper/command (std_msgs/Float32, 0=close 1=open)
release → /gripper/command (std_msgs/Float32)
push → /base/cmd_vel (geometry_msgs/Twist)
look_at → camera PTZ control
detect_objects → /perception/objects (vision_msgs/Detection3DArray)
get_pose → /base/odom + /arm/joint_states
speak → /speech/tts (std_msgs/String)
play_gesture → /arm/joint_trajectory (pre-defined trajectories)
wait → no topic (sleep)
emergency_stop → /safety/estop (std_msgs/Bool)
Demo Output
Natural language → task execution (mock mode):
[Result]:
Task completed in 6 steps
▸ look_at → table
▸ detect_objects → cup detected
▸ navigate_to → table
▸ move_arm → grasp position
▸ grasp → cup_01
▸ speak → “已拿到水杯” (cup fetched)
[Result]:
Task completed in 6 steps
▸ navigate_to → waypoint_1
▸ look_at → front
▸ speak → “waypoint_1 clear”
▸ navigate_to → waypoint_2
▸ look_at → left
▸ speak → “waypoint_2 clear”
Integration Checklist
To integrate a robot with ClawsJoy Robotics:
-
Arm: publish
/arm/joint_states, subscribe/arm/joint_trajectory -
Gripper: subscribe
/gripper/command(Float32, 0=close 1=open) -
Base: subscribe
/base/cmd_vel, publish/base/odom -
Camera: publish
/camera/rgb,/camera/depth -
Perception: publish
/perception/objects -
Speech: subscribe
/speech/tts -
Safety: subscribe
/safety/estop
Then set mock_mode=False and run.
Code
https://github.com/your-org/clawsjoy_robotics
12 primitives defined in motion_primitives.yaml. Full topic mapping in bridge/ros2_bridge.py. Task planner in planner/planner.py.
Questions for the community
-
Are these 12 primitives sufficient, or should we add/remove some?
-
Is
trajectory_msgs/JointTrajectorythe right interface formove_arm, or should we use ROS/2 Actions? -
Should we adopt the existing
ros2_controlinterfaces instead of defining new topics? -
Is this worth standardizing, or is every robot too different?
Looking forward to feedback.
3 posts - 2 participants
ROS Discourse General: Cad to urdf conversion
If you’re a robotics engineer, you’ve probably lost hours to URDF generation.
Not because the robot is complex but because the tooling is.
Renaming mates. Fixing joint axes. Recreating reference frames. Starting over because the CAD came from the “wrong” software.
I got tired of that workflow, so I built Jointly.
Upload a STEP assembly then get a draft URDF with inferred joints, inertia, collision meshes, and a live 3D preview.
It’s not magic , you’ll still review the result. But it turns hours of manual work into a couple of minutes.
I’d love to test it on real-world assemblies. If you have a CAD file that breaks your current exporter, Try it Now
3 posts - 2 participants
ROS Discourse General: Ros2-dev-suite, a StudioCode extension
As shared in a lightning talk at ROSConFr: I have finally completed and “clauded” a comprehensive VS Code extension for ROS 2 development: a unified explorer, live parameter tuner, service/topic/action caller, log viewer, and syntax highlighting for interface files.
My favorite features of the extension, among others:
- Dynamically changing node ROS parameters at runtime via a YAML panel and comparing live params vs. edits: very handy for tuning PIDs, covariances, etc. Possibility to edit an existing params yaml file, inject missing parameters or view the all available parameters
- Displaying the logs of a namespace-filtered node in the output section of the IDE: useful while tuning a single set of nodes whose logs would otherwise be lost in a single launch command.
- Sending topics, services, or actions at runtime with predefined templates and QoS definitions.
- … plenty of others! I invite you to test it or check out the README section.
The main structure of the package is quite simple: usual ROS 2 CLIs are used in virtual shells to perform the functions, so no rclpy dependencies are required.
Available on:
GitHub (to install locally from the .vsix file, and for developers to edit, compile, etc.): GitHub - Tanneguydv/ros2-dev-suite: A comprehensive VS Code extension for ROS 2 development · GitHub
Visual Studio Marketplace (to directly install the extension from the IDE): ROS 2 Dev Suite - Visual Studio Marketplace
This package is a child of GitHub - ErickKramer/nvim-ros2: nvim-ros2 is a simple lua plugin that adds useful features to enhance your development workflow while developing ROS 2 modules. · GitHub , incorporating the latest pull request by Thibault Cozic for workspace navigation, ROS 2 tuner, etc. As I do not use Neovim, these features have been adapted to VS Code.
Some Screenshots:
Parameter tuning
Topic sender
Action caller
Service caller and yaml details (on mouse contextual window)
Logging filter for Output section of IDE
Dedicated notification of selected dying node
Filter left panel display by namespace
1 post - 1 participant
ROS Discourse General: 🍺 ros2-jazzy is now available on Homebrew!
All three ROS 2 distros are now native on Homebrew-macOS:
brew tap idesign0/ros2
brew install ros2-humble
brew install ros2-jazzy
brew install ros2-kilted
One tap to get ROS 2 Jazzy with full simulation and robotics stack support:
Gazebo (gz-sim8) — Gazebo Harmonic simulation out of the box
ros2_control — Hardware abstraction & controllers
MoveIt 2 — Motion planning
Nav2 — Autonomous navigation
No Docker. No VMs. Native macOS.
And the best part? These aren’t one-time snapshots — they stay in sync with upstream and will keep getting updated as the ecosystem evolves. ![]()
What’s next? I’ve been quietly collecting -Werror flag failures from Apple Clang across all three distros. Fixing them upstream should meaningfully improve code quality across the stack.
Want to try MoveIt 2 or TurtleBot4 tutorials on macOS? I’ve patched them for all available distros:
TurtleBot4 tutorials (Jazzy): https://lnkd.in/e2ZXMXBn
MoveIt 2 tutorials (Jazzy): https://lnkd.in/eWwNCT-G
Project Links:
Ros2_macos repo: https://lnkd.in/ehEtTSJz
Homebrew repo: https://lnkd.in/ek5zDAQB
2 posts - 2 participants
ROS Discourse General: Sony AI's Ace (Nature cover, beat a pro table tennis player) — running on ROS 2
Can you believe this is running ROS 2? ![]()
Sony’s Ace Robot Beats Top Table Tennis Pros in Real Matches
Sony AI’s Ace just landed on the cover of Nature — the first robot ever to beat a professional table tennis player.
Let that sink in for a second:
• It tracks a ball moving at 20 m/s with spin over 9,000 rpm
• Perceives it in 10.2 ms (event-based vision)
• Decides and swings on a 1 kHz control loop
• And returns the ball at up to 19.6 m/s
This is physical AI right at the edge of what’s possible — and we’ve been working on the ROS 2 integration and support underneath it. The fact that ROS 2 holds up in a system this demanding says a lot about where the ecosystem is heading.
Huge respect to the Sony AI team. Take a look ![]()
11 posts - 6 participants
ROS Discourse General: A tutorial to make your quadruped robot on ROS
Hello guys !
I made a tutorial to make your own quadruped using ros2 jazzy !
If you have any feed back I am happy to hear it
1 post - 1 participant
ROS Discourse General: Rclnodejs 2.1: Native ESM for a Web-Native ROS 2 SDK
Hi all,
rclnodejs 2.1.0 is out — and it’s a step toward making rclnodejs a web-native SDK for ROS 2: a platform for bringing ROS 2 to the browser and the modern JavaScript ecosystem. With 2.1.0, the whole package is now native ESM, so building web dashboards, teleop UIs, and browser bridges on ROS 2 feels native to today’s web tooling — with the full ROS 2 runtime still underneath whenever you need real nodes.
TL;DR — 2.1.0 makes rclnodejs native ESM end-to-end.
import rclnodejs from 'rclnodejs'just works, the browser SDK (rclnodejs/web) brings ROS 2 to the web, and existingrequire()nodes keep running untouched — the full ROS 2 runtime is still underneath.
A web-native SDK for ROS 2
- ROS 2 on the web — reach ROS 2 from a web page with
rclnodejs/web: typed APIs over WebSocket, no proxy, no codegen. - Native ESM — first-class
importand top-levelawait, ready for Vite/esbuild and the modern web toolchain. - Full ROS 2 runtime underneath — real nodes, pub/sub, services, actions, parameters, lifecycle, whenever you need them.
- Backward compatible — every existing CommonJS (
require) project upgrades with zero code changes.
One package, both module systems
// Modern Node / browser — ESM
import rclnodejs from 'rclnodejs'; // full ROS 2 node API
import { connect } from 'rclnodejs/web'; // typed browser SDK
// Existing CommonJS nodes — unchanged
const rclnodejs = require('rclnodejs');
Where this is heading
Each release moves rclnodejs one step closer to a typed, web-native way into ROS 2:
- 2.0.0
— a typed browser SDK (rclnodejs/web) backed by a capability runtime that exposes only whatweb.jsondeclares, with HTTPcall/publishfor non-JS clients. - 2.1.0
— native ESM across the whole package, so rclnodejs sits naturally alongside the rest of your web stack.
The arc: from “a Node.js client that happens to run in browsers” → “a typed, allow-listed Web SDK for ROS 2”
Try it
npm i rclnodejs
SDK guide: web/README.md
JS demo (no toolchain): demo/web/javascript/
TS + Vite demo: demo/web/typescript/
Feedback welcome — especially from anyone wiring ROS 2 into web frontends. ![]()
Cheers,
Minggang
1 post - 1 participant
ROS Discourse General: Anomaly Detection. Beta testers wanted
Hi, I used to work at a robotics startup that built robotic dishwashers. (https://armstrong.ai/) And part of my job was to set up diagnostics, monitoring and alerting.
Aside from not being the most interesting part of my job, it was just plain tedious to manually set (and continually tune) thresholds for various signals, topics, etc. I frequently thought it would be nice to have a system that would automate that part of my job and now that the company has closed, I built it.
Now I have reached the point where the useful next step is real robots. The system performs well on recorded public datasets and on some production infrastructure (see below), but what I do not have yet is enough hours on a variety of real robots, doing real work.
Details are here at the Transitive Robotics website:
What it is
The system watches your robot’s topics and tells you when something is wrong. No threshold tuning, no hardcoded rules. It learns what normal looks like on your robot, then flags and reports anomalies in real time.
How to get involved
Reply to this thread or email shane@targetnode.ai. I will help you get it installed and monitored.
What you get and what I am asking for
What you get:
-
Anomaly detection for free on your robot with no manual threshold tuning to maintain.
-
Direct influence over the direction of the system/project. I want to know what is missing, what is confusing, and what breaks on real robots in production.
What I am asking for:
- Honest and detailed feedback
Where it has been tested
I evaluated the system against public datasets that cover real hardware faults across very different platforms. The system has been tested successfully on the following datasets:
-
CASPER. A UR3e collaborative robot arm with real IMU fault data, from Cardiff University. (paper)
-
PADRE, Parrot Bebop 2. Real propeller damage on a quadrotor, recorded from onboard IMUs. (paper)
-
PADRE, 3DR Solo. Real propeller damage on a second quadrotor airframe, with IMU and barometer data.
-
ALFA. A CarbonZ T-28 fixed-wing aircraft with real engine and actuator faults, from Carnegie Mellon University’s AirLab. (data)
-
UAV-SEAD. A large set of real PX4 flights with naturally occurring state-estimation anomalies, from Istanbul Technical University. (paper)
Additionally, I am running the system on my production servers. They are not robots, per se, but they are live production systems that get used every day. Right now the system is watching CPU, memory, disk/network operations (29 signals total) all without me setting or tuning thresholds. In the last 200 hours of operation (since Tuesday, June 16, 2026) there have been no false alerts.
Thanks for checking out this post and if you have any questions, reach out to me at shane@targetnode.ai
2 posts - 2 participants
ROS Discourse General: VL53L0X Time-of-Flight sensor as a Nav2 obstacle layer (ESP32 + ROS 2 Humble)

Sharing a small open-source project that integrates a low-cost VL53L0X Time-of-Flight sensor into the Nav2 costmap as an obstacle source, in case it’s useful to anyone working with cheap range sensors on small robots.
Pipeline
VL53L0X --I2C–> ESP32 --USB serial–> serial_bridge → sensor_msgs/Range
→ tof_to_scan → sensor_msgs/LaserScan → nav2_costmap_2d::ObstacleLayer
What’s included
- ESP32 firmware (Arduino, Pololu VL53L0X library) streaming distance over serial with sensor-disconnect recovery
- An rclpy serial-bridge node publishing sensor_msgs/Range, with a threaded reader and automatic serial reconnect
- A Range → LaserScan converter that synthesizes a configurable narrow fan from the single beam (default ±0.15 rad, 31 rays), emitting +inf for out-of-range readings so the obstacle layer can raytrace-clear
- A full Nav2 costmap config wiring the scan into local and global costmaps (marking + clearing, inf_is_valid: true)
- RViz config and a troubleshooting guide
Built and tested on ROS 2 Humble / Ubuntu 22.04. Python packages (ament_python).
Scope / limitations (up front)
This is a supplementary obstacle sensor, not a LiDAR replacement — a single narrow-FOV ToF sees one thin cone.
One thing I’d be curious about others’ experience on: raytrace clearing on a stationary base leaves residual cells at the edges of the cone, since the clearing rays never cross them. It resolves once the robot moves and the cone sweeps, but I’d be interested whether anyone has handled static-case clearing for single-beam sensors more elegantly. Widening the FOV and increasing ray count helped, but felt like a workaround.
A config gotcha that may save someone time: obstacle marking worked but clearing silently didn’t, until I set obstacle_max_range < raytrace_max_range, with raytrace_max_range equal to the sensor’s true range_max. A mismatch there breaks clearing while marking still functions, so it presents as “obstacles never disappear.”
Feedback and suggestions welcome.
1 post - 1 participant
ROS Discourse General: Embeddable React telemetry components — a browser ground station for MAVROS
I maintain Altara, a set of MIT-licensed React components for real-time robotics telemetry (PFD, moving map, gauges, event log), and I wrote up building a small drone ground station with them that talks to MAVROS over rosbridge.
The thing I was trying to solve: I wanted a status dashboard our team could open in a browser tab and drop into our own app, rather than running a separate native GCS. So the components are embeddable and themeable rather than a standalone tool.
Writeup (the rosbridge/MAVROS wiring is the interesting part): [ Building a real-time drone ground control station in React - DEV Community ]
Live demo: [ Altara Demo ] · Source: [https://github.com/JayaSaiKishanChapparam/altara\]
If you’ve built browser dashboards for a ROS2 stack, I’d like to know what you ended up reading off your topics, and where existing tools forced you into a standalone app when you wanted something embedded.
4 posts - 2 participants
ROS Discourse General: KRS Unleashed: Easier Hardware Acceleration Prototyping on FPGA
Hey All,
I want to present KRS Unleashed, the tool I am now developing/refactoring/extending since 1 year as part of my PhD.
Some of you might still know KRS (short for Kria Robotic Stack as originally developed by Xilinx/AMD for their Kria platform) as the toolchain developed until 2023 by the ROS 2 Hardware Acceleration Working Group · GitHub .
(Short Summary for those who don’t)
It was a proof-of-concept framework that allowed to synthesize bitstreams, create a sysroot and cross-compile application against it to create robotics applications running on KV260, KR260 (and also claimed jetson, Ultra96v2,.. but i have never tested/verified that so far). So basically the main point of it is to replace this “docker container to compile” flow with ROS 2 colcon mixin and in parallel integrate all the necessary and optional things for hardware acceleration like sysroot creation or vendor-driven bitstream synthesis in a ROS 2 command.
The flow works, but I found it really hard to use:
- long build times whenever you cleaned your build/install folders, as even the sysroot and bitstream needed to resynthesize when you just changed a variable in a package (if you know what you are doing you can keep the untouched compiled packages but its not really stable nor trivial)
- cross-references and dependency cycles made it hard to change configuration like different Vitis version, other firmware OS,..
- hard to understand what each package actually did and which ones were necessary for your task - the original guide simply copied all available packages in
Basically it wasn’t really fun to use and whenever you start with a new project, you fight cmake configurations for a while until you can start coding..
My tool refactored these individual components into 3 separate logical workspaces:
- os → for firmware and sysroot creation - allows to reuse across projects (save lots of memory space, no rebuild necessary, parallel development possible by different team)
- vitis → vendor-driven toolchain necessary to automate your “accelerator bitstream flow”. I refactored also the automation into a nice Python CLI scripted way such that I can also use the Vitis workspace and manually adjust things, but this is more a FPGA developer nice-to-have. Could also be replaced with a flow for other accelerators
- krs → lightweight integration of firmware via single package, that provides the colcon mixin integration. Further a tracetools-kernels package that allows to trace arbitrary code regions in any ROS 2 application extending ros-tracing.
You can also use any of these components in isolated areas - I use for example also vitis + os for standalone faster iteration on host code variations. It might be a little bit harder to setup for the first time, but I can iterate really fast with it (built times up to 80x faster) and the setup is the same for all projects so once you understand it, its relatively easy and doesn’t require changes all over the project but just in very small, well defined areas.
I also created a Hackster Series for the brave.
I continue to develop it, current public version is still humble but I already have an internal jazzy version which I will release once I published a new paper.
Github: GitHub - TUD-ADS/KRS-Unleashed · GitHub
Hackster Series (5 Parts): 1. Getting Started
Paper: https://ieeexplore.ieee.org/document/11231288/
1 post - 1 participant
ROS Discourse General: Minimum CMake version to support Humble at this time
REP 2000 specifies MacOS support for CMake 3.14.4 in Humble:
This is the lowest number for the whole Humble release.
However, MacOS has this note:
" ** " means that the dependency may see multiple version changes, because the dependency uses a package manager that continually updates the dependency without a stable API.
I don’t work with MacOS myself, so I don’t know how it behaves. Is it still needed nowadays to support 3.14.4 to get full support for Humble on MacOS, or can I just ignore this and upgrade to 3.16.3 from Focal (assuming that MacOS currently uses a much newer version)?
And on the other hand: Homebrew Formulae: cmake shows CMake version 4.3.4 . Does it mean that even people building Humble on MacOS will use this version? So do I need to make sure the package also builds with this version?
3 posts - 2 participants
ROS Discourse General: Dual-Arm Nero Reinforcement Learning in Isaac Lab: Reach Task Training Example
Robotic manipulation remains one of the most important research directions in embodied AI. While traditional kinematics-based controllers provide stable motion execution, they often struggle in unstructured environments where adaptability is required.
Recent advances in Reinforcement Learning (RL) have enabled robotic arms to learn task-oriented behaviors directly from interaction, making it possible to achieve robust control policies without manually designing every motion strategy.
In this project, we extend the original SO-ARM101 Isaac Lab implementation by integrating the AgileX Dual-Arm Nero Manipulator, allowing developers to quickly train and validate dual-arm RL policies using NVIDIA Isaac Lab.
Reposity
Open-source implementation:
GitHub - smalleha/isaac_so_arm101: Isaac Lab external project for SO-ARM100/101 arm robot. · GitHub
Project Structure
├── robots
│ ├── dual_nero
│ │ ├── dual_nero.py
│ │ ├── __init__.py
│ │ ├── meshes
│ │ └── urdf
│ │ └── dual_nero.urdf
├── scripts
│ ├── rl_games
│ │ ├── play.py
│ │ └── train.py
│ └── zero_agent.py
├── tasks
│ ├── __init__.py
│ └── reach
│ ├── agents
│ ├── dual_nero_joint_pos_env_cfg.py
│ ├── dual_nero_reach_env_cfg.py
│ ├── __init__.py
│ └── mdp
└── ui_extension_example.py
Key additions include:
| Column 1 | Column 2 |
|---|---|
| Component | Description |
| rl_games | RL-Games training framework |
| dual_nero_reach_env_cfg.py | Reach task environment definition |
| dual_nero_joint_pos_env_cfg.py | Joint position control configuration |
| dual_nero | Dual-arm robot model |
3. Importing the Robot into Isaac Lab
3.1 Preparing the URDF
Before importing the robot into Isaac Lab, mesh references inside the URDF should be converted to relative paths.
For example:
<link name="base_link">
<inertial>
<origin rpy="0 0 0" xyz="-0.0592395620981769 -0.068642440505388 0.0562764736144042"/>
<mass value="4.46524857458863"/>
<inertia ixx="0.0608289280191989" ixy="-2.54649959130438E-06" ixz="1.11851948046933E-07" iyy="0.0218722514454004" iyz="-0.000689477252402357" izz="0.0680524540174318"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="../meshes/base_link.dae"/>
</geometry>
<material name="">
<color rgba="0.776470588235294 0.756862745098039 0.737254901960784 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="../meshes/base_link.dae"/>
</geometry>
</collision>
</link>
This ensures that the asset loader can correctly locate mesh resources during simulation.
3.2 Creating the Robot Configuration
Next, create a robot configuration file:
isaac_so_arm101/robots/dual_nero/dual_nero.py
This file defines:
-
Robot articulation properties
-
Joint stiffness and damping
-
Actuator configuration
-
Initial joint states
-
Gripper settings
The resulting DUAL_NERO_CFG object becomes the robot asset used by Isaac Lab during training.
from pathlib import Path
import isaaclab.sim as sim_utils
from isaaclab.actuators import ImplicitActuatorCfg
from isaaclab.assets.articulation import ArticulationCfg
TEMPLATE_ASSETS_DATA_DIR = Path(__file__).resolve().parent
DUAL_NERO_CFG = ArticulationCfg(
spawn=sim_utils.UrdfFileCfg(
fix_base=True,
merge_fixed_joints=False,
replace_cylinders_with_capsules=True,
asset_path=f"{TEMPLATE_ASSETS_DATA_DIR}/urdf/dual_nero.urdf",
activate_contact_sensors=False, # set as false while waiting for capsule implementation
rigid_props=sim_utils.RigidBodyPropertiesCfg(
disable_gravity=False,
max_depenetration_velocity=5.0,
),
articulation_props=sim_utils.ArticulationRootPropertiesCfg(
enabled_self_collisions=True,
solver_position_iteration_count=8,
solver_velocity_iteration_count=0,
),
joint_drive=sim_utils.UrdfConverterCfg.JointDriveCfg(
gains=sim_utils.UrdfConverterCfg.JointDriveCfg.PDGainsCfg(stiffness=0, damping=0)
),
),
init_state=ArticulationCfg.InitialStateCfg(
rot=(1.0, 0.0, 0.0, 0.0),
joint_pos={
"left_joint.*": 0.0,
"right_joint.*": 0.0,
"left_gripper_joint.*": 0.0,
"right_gripper_joint.*": 0.0,
},
# Set initial joint velocities to zero
joint_vel={".*": 0.0},
),
actuators={
"arm": ImplicitActuatorCfg(
joint_names_expr=["left_joint.*", "right_joint.*"],
effort_limit=25.0,
velocity_limit=1.5,
stiffness={
"left_joint1": 200.0,
"left_joint2": 170.0,
"left_joint3": 120.0,
"left_joint4": 80.0,
"left_joint5": 50.0,
"left_joint6": 20.0,
"left_joint7": 10.0,
"right_joint1": 200.0,
"right_joint2": 170.0,
"right_joint3": 120.0,
"right_joint4": 80.0,
"right_joint5": 50.0,
"right_joint6": 20.0,
"right_joint7": 10.0
},
damping={
"left_joint1": 100.0,
"left_joint2": 60.0,
"left_joint3": 70.0,
"left_joint4": 24.0,
"left_joint5": 20.0,
"left_joint6": 10.0,
"left_joint7": 5,
"right_joint1": 100.0,
"right_joint2": 60.0,
"right_joint3": 70.0,
"right_joint4": 24.0,
"right_joint5": 20.0,
"right_joint6": 10.0,
"right_joint7": 5,
},
),
"gripper": ImplicitActuatorCfg(
joint_names_expr=["left_gripper_joint.*","right_gripper_joint.*"],
effort_limit_sim=22, # Increased from 1.9 to 2.5 for stronger grip
velocity_limit_sim=1.5,
stiffness=800.0, # Increased from 25.0 to 60.0 for more reliable closing
damping=20.0, # Increased from 10.0 to 20.0 for stability
),
},
soft_joint_pos_limit_factor=0.9,
)
Create an init.py file inside the dual_nero directory so that Python recognizes it as a package.
4. Building the Reach Environment
Two environment configuration files are required:
tasks/reach/
├── dual_nero_joint_pos_env_cfg.py
└── dual_nero_reach_env_cfg.py
4.1 Joint Position Environment Configuration
dual_nero_joint_pos_env_cfg.py specifies:
-
Controlled joints
-
End-effector links
-
Action spaces
-
Command targets
import math
import isaaclab_tasks.manager_based.manipulation.reach.mdp as mdp
from isaaclab.utils import configclass
from isaac_so_arm101.robots import DUAL_NERO_CFG # noqa: F401
from isaac_so_arm101.tasks.reach.dual_nero_reach_env_cfg import Dual_NeroReachEnvCfg
from isaaclab.assets.articulation import ArticulationCfg
@configclass
class Dual_Nero_ReachEnvCfg(Dual_NeroReachEnvCfg):
def __post_init__(self):
# post init of parent
super().__post_init__()
# switch robot to OpenArm
self.scene.robot = DUAL_NERO_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot",)
# override rewards
self.rewards.left_end_effector_position_tracking.params["asset_cfg"].body_names = ["left_gripper_base"]
self.rewards.left_end_effector_position_tracking_fine_grained.params["asset_cfg"].body_names = [
"left_gripper_base"
]
self.rewards.left_end_effector_orientation_tracking.params["asset_cfg"].body_names = ["left_gripper_base"]
self.rewards.right_end_effector_position_tracking.params["asset_cfg"].body_names = ["right_gripper_base"]
self.rewards.right_end_effector_position_tracking_fine_grained.params["asset_cfg"].body_names = [
"right_gripper_base"
]
self.rewards.right_end_effector_orientation_tracking.params["asset_cfg"].body_names = ["right_gripper_base"]
# override actions
self.actions.left_arm_action = mdp.JointPositionActionCfg(
asset_name="robot",
joint_names=[
"left_joint.*",
],
scale=0.5,
use_default_offset=True,
)
self.actions.right_arm_action = mdp.JointPositionActionCfg(
asset_name="robot",
joint_names=[
"right_joint.*",
],
scale=0.5,
use_default_offset=True,
)
# override command generator body
# end-effector is along z-direction
self.commands.left_ee_pose.body_name = "left_gripper_base"
self.commands.right_ee_pose.body_name = "right_gripper_base"
@configclass
class Dual_Nero_ReachEnvCfg_PLAY(Dual_Nero_ReachEnvCfg):
def __post_init__(self):
# post init of parent
super().__post_init__()
# make a smaller scene for play
self.scene.num_envs = 50
self.scene.env_spacing = 2.5
# disable randomization for play
self.observations.policy.enable_corruption = False
4.2 Reach Task Definition
dual_nero_reach_env_cfg.py contains the full RL environment definition.
This includes:
1.Scene Configuration
-
Ground plane
-
Lighting
-
Robot asset
2.Command Generation
3.Observation Space
4.Reward Design
5.Curriculum Learning
6.Episode Settings
import math
from dataclasses import MISSING
import isaaclab.sim as sim_utils
from isaaclab.assets import ArticulationCfg, AssetBaseCfg
from isaaclab.envs import ManagerBasedRLEnvCfg
from isaaclab.managers import ActionTermCfg as ActionTerm
from isaaclab.managers import CurriculumTermCfg as CurrTerm
from isaaclab.managers import EventTermCfg as EventTerm
from isaaclab.managers import ObservationGroupCfg as ObsGroup
from isaaclab.managers import ObservationTermCfg as ObsTerm
from isaaclab.managers import RewardTermCfg as RewTerm
from isaaclab.managers import SceneEntityCfg
from isaaclab.managers import TerminationTermCfg as DoneTerm
from isaaclab.scene import InteractiveSceneCfg
from isaaclab.utils import configclass
from isaaclab.utils.noise import AdditiveUniformNoiseCfg as Unoise
import isaaclab_tasks.manager_based.manipulation.reach.mdp as mdp
##
# Scene definition
##
@configclass
class Dual_NeroReachSceneCfg(InteractiveSceneCfg):
"""Configuration for the scene with a robotic arm."""
# world
ground = AssetBaseCfg(
prim_path="/World/ground",
spawn=sim_utils.GroundPlaneCfg(),
init_state=AssetBaseCfg.InitialStateCfg(pos=(0.0, 0.0, 0)),
)
# robots
robot: ArticulationCfg = MISSING
# lights
light = AssetBaseCfg(
prim_path="/World/light",
spawn=sim_utils.DomeLightCfg(color=(0.75, 0.75, 0.75), intensity=2500.0),
)
##
# MDP settings
##
@configclass
class CommandsCfg:
"""Command terms for the MDP."""
left_ee_pose = mdp.UniformPoseCommandCfg(
asset_name="robot",
body_name=MISSING,
resampling_time_range=(4.0, 4.0),
debug_vis=True,
ranges=mdp.UniformPoseCommandCfg.Ranges(
pos_x=(0.5, 0.5),
pos_y=(0.15, 0.25),
pos_z=(0.3, 0.5),
roll=(-math.pi / 6, math.pi / 6),
pitch=(3 * math.pi / 2, 3 * math.pi / 2),
yaw=(8 * math.pi / 9, 10 * math.pi / 9),
),
)
right_ee_pose = mdp.UniformPoseCommandCfg(
asset_name="robot",
body_name=MISSING,
resampling_time_range=(4.0, 4.0),
debug_vis=True,
ranges=mdp.UniformPoseCommandCfg.Ranges(
pos_x=(0.5, 0.5),
pos_y=(-0.25, -0.15),
pos_z=(0.3, 0.5),
roll=(-math.pi / 6, math.pi / 6),
pitch=(3 * math.pi / 2, 3 * math.pi / 2),
yaw=(8 * math.pi / 9, 10 * math.pi / 9),
),
)
@configclass
class ActionsCfg:
"""Action specifications for the MDP."""
left_arm_action: ActionTerm = MISSING
right_arm_action: ActionTerm = MISSING
@configclass
class ObservationsCfg:
"""Observation specifications for the MDP."""
@configclass
class PolicyCfg(ObsGroup):
"""Observations for policy group."""
# observation terms (order preserved)
left_joint_pos = ObsTerm(
func=mdp.joint_pos_rel,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"left_joint.*",
],
)
},
noise=Unoise(n_min=-0.01, n_max=0.01),
)
right_joint_pos = ObsTerm(
func=mdp.joint_pos_rel,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"right_joint.*",
],
)
},
noise=Unoise(n_min=-0.01, n_max=0.01),
)
left_joint_vel = ObsTerm(
func=mdp.joint_vel_rel,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"left_joint.*",
],
)
},
noise=Unoise(n_min=-0.01, n_max=0.01),
)
right_joint_vel = ObsTerm(
func=mdp.joint_vel_rel,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"right_joint.*",
],
)
},
noise=Unoise(n_min=-0.01, n_max=0.01),
)
left_pose_command = ObsTerm(func=mdp.generated_commands, params={"command_name": "left_ee_pose"})
right_pose_command = ObsTerm(func=mdp.generated_commands, params={"command_name": "right_ee_pose"})
left_actions = ObsTerm(func=mdp.last_action, params={"action_name": "left_arm_action"})
right_actions = ObsTerm(func=mdp.last_action, params={"action_name": "right_arm_action"})
def __post_init__(self):
self.enable_corruption = True
self.concatenate_terms = True
# observation groups
policy: PolicyCfg = PolicyCfg()
@configclass
class EventCfg:
"""Configuration for events."""
reset_robot_joints = EventTerm(
func=mdp.reset_joints_by_scale,
mode="reset",
params={
"position_range": (0.5, 1.5),
"velocity_range": (0.0, 0.0),
},
)
@configclass
class RewardsCfg:
"""Reward terms for the MDP."""
left_end_effector_position_tracking = RewTerm(
func=mdp.position_command_error,
weight=-0.2,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"command_name": "left_ee_pose",
},
)
right_end_effector_position_tracking = RewTerm(
func=mdp.position_command_error,
weight=-0.25,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"command_name": "right_ee_pose",
},
)
left_end_effector_position_tracking_fine_grained = RewTerm(
func=mdp.position_command_error_tanh,
weight=0.1,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"std": 0.1,
"command_name": "left_ee_pose",
},
)
right_end_effector_position_tracking_fine_grained = RewTerm(
func=mdp.position_command_error_tanh,
weight=0.2,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"std": 0.1,
"command_name": "right_ee_pose",
},
)
left_end_effector_orientation_tracking = RewTerm(
func=mdp.orientation_command_error,
weight=-0.1,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"command_name": "left_ee_pose",
},
)
right_end_effector_orientation_tracking = RewTerm(
func=mdp.orientation_command_error,
weight=-0.1,
params={
"asset_cfg": SceneEntityCfg("robot", body_names=MISSING),
"command_name": "right_ee_pose",
},
)
# action penalty
action_rate = RewTerm(func=mdp.action_rate_l2, weight=-0.0001)
left_joint_vel = RewTerm(
func=mdp.joint_vel_l2,
weight=-0.0001,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"left_joint.*",
],
)
},
)
right_joint_vel = RewTerm(
func=mdp.joint_vel_l2,
weight=-0.0001,
params={
"asset_cfg": SceneEntityCfg(
"robot",
joint_names=[
"right_joint.*",
],
)
},
)
@configclass
class TerminationsCfg:
"""Termination terms for the MDP."""
time_out = DoneTerm(func=mdp.time_out, time_out=True)
@configclass
class CurriculumCfg:
"""Curriculum terms for the MDP."""
action_rate = CurrTerm(
func=mdp.modify_reward_weight,
params={"term_name": "action_rate", "weight": -0.005, "num_steps": 4500},
)
left_joint_vel = CurrTerm(
func=mdp.modify_reward_weight,
params={"term_name": "left_joint_vel", "weight": -0.001, "num_steps": 4500},
)
right_joint_vel = CurrTerm(
func=mdp.modify_reward_weight,
params={"term_name": "right_joint_vel", "weight": -0.001, "num_steps": 4500},
)
##
# Environment configuration
##
@configclass
class Dual_NeroReachEnvCfg(ManagerBasedRLEnvCfg):
"""Configuration for the reach end-effector pose tracking environment."""
# Scene settings
scene: Dual_NeroReachSceneCfg = Dual_NeroReachSceneCfg(num_envs=4096, env_spacing=2.5)
# Basic settings
observations: ObservationsCfg = ObservationsCfg()
actions: ActionsCfg = ActionsCfg()
commands: CommandsCfg = CommandsCfg()
# MDP settings
rewards: RewardsCfg = RewardsCfg()
terminations: TerminationsCfg = TerminationsCfg()
events: EventCfg = EventCfg()
curriculum: CurriculumCfg = CurriculumCfg()
def __post_init__(self):
"""Post initialization."""
# general settings
self.decimation = 2
self.sim.render_interval = self.decimation
self.episode_length_s = 24.0
self.viewer.eye = (3.5, 3.5, 3.5)
# simulation settings
self.sim.dt = 1.0 / 60.0
\`\`\`
**### 4.3 Registering the Environment**
Register the task inside:\`src/isaac_so_arm101/tasks/reach/\__init_\_.py\`
\`\`\`PYTHON
gym.register(
id="Isaac-Dual-Nero-Reach-v0",
entry_point="isaaclab.envs:ManagerBasedRLEnv",
kwargs={
"env_cfg_entry_point":f"{\__name_\_}.dual_nero_joint_pos_env_cfg:Dual_Nero_ReachEnvCfg",
"rsl_rl_cfg_entry_point": f"{agents.\__name_\_}.rsl_rl_ppo_cfg:ReachPPORunnerCfg",
"rl_games_cfg_entry_point": f"{agents.\__name_\_}:rl_games_ppo_cfg.yaml",
},
disable_env_checker=True,
)
5. Training the Reach Policy
Step 1.Activate the Isaac Lab Environment
conda activate env_isaaclab
Step 2.Navigate to the project directory:
cd isaac_so_arm101
Step 3.Train the whole project
Option 1:RSL-RL
- Train:
uv run train \
--task Isaac-Dual-Nero-Reach-v0 \
--headless
- Evaluate:
uv run play \
--task Isaac-Dual-Nero-Reach-v0
- Training result:
dual_nero_rsl_rl.gif

Option 2: RL-Games
- Train:
python3 scripts/rl_games/train.py \
--task Isaac-Dual-Nero-Reach-v0 \
--headless
- Evaluate:
python3 scripts/rl_games/play.py \
--task Isaac-Dual-Nero-Reach-v0
- Training result:
dual_nero_rl_games.gif

6. Results and Observations
Both frameworks successfully learn the dual-arm reaching task.
However, in our experiments:
-
RL-Games converges faster
-
Motion trajectories appear smoother
-
Final reaching accuracy is generally higher
For relatively complex robot morphologies such as dual-arm manipulators, RL-Games currently provides more stable performance and is recommended as the default training backend.
FAQ
Q1: Why is my Dual-Nero robot collapsing or shaking violently after loading the URDF?
This is usually caused by incorrect actuator parameters or unrealistic inertial properties.
Common causes include:
-
Joint stiffness set too high
-
Damping values too low
-
Incorrect mass distribution in the URDF
-
Self-collision configuration issues
-
Unstable simulation timestep
Before starting RL training, verify that the robot can remain stable under gravity using only PD control.
Quick check: If the robot cannot stand still without RL, the issue is likely in the robot model rather than the training algorithm.
Q2: Why does the reward improve, but the robot never reaches the target accurately?
A rising reward does not always indicate successful task completion.
Typical reasons include:
-
Reward weights are unbalanced
-
Orientation rewards dominate position rewards
-
Action penalties are too strong
-
Command sampling range is too large
-
End-effector link is incorrectly configured
In most reach tasks, incorrect reward shaping is the primary reason for poor final accuracy.
Q3: How do I verify that the end-effector link is configured correctly?
One of the most common mistakes in Isaac Lab reach tasks is assigning the wrong end-effector body.
For Dual-Nero, the target link should be:
left_gripper_base
right_gripper_base
Symptoms of an incorrect configuration include:
-
Reward remains low
-
Robot moves randomly
-
Training appears to converge but fails visually
-
End-effector does not move toward the target marker
Always verify the body name in Isaac Sim before launching large-scale training.
Q4: Why does RL-Games perform better than RSL-RL for this task?
Both frameworks are PPO-based, but their implementations differ.
For large-scale manipulation environments:
RL-Games generally scales better with thousands of parallel environments
PPO updates are often more stable
Training throughput is higher on modern GPUs
For Dual-Nero reach experiments, RL-Games typically achieves smoother trajectories and faster convergence.
However, results may vary depending on reward design and task complexity.
Q5: My policy works in simulation but fails on the real robot. Why?
This is the most common Sim-to-Real issue.
Possible causes include:
-
Joint friction mismatch
-
Encoder noise
-
Latency differences
-
Payload variations
-
Inaccurate motor models
-
Unmodeled cable effects
To improve transfer performance:
-
Apply domain randomization
-
Add observation noise
-
Randomize dynamics parameters
-
Validate trajectories at low speed first
Successful simulation training is only the first step toward real-world deployment.
Have Question?
If you encounter any issues with environment installation, parameter configuration, or RL training, feel free to leave your questions for further discussion.
1 post - 1 participant
ROS Discourse General: Open-source ROS2 LiDAR robot vacuum cleaner
Hello, would you be interested in building a ROS2 vacuum cleaner robot?
If yes
- Build/develop vs convert existing?
- 3D print vs off-the-shelf?
- Convert existing - root or swap board?
I’d really appreciate your input.
As an example of what I’m doing
- I have connected my vacuum to ROS including /scan, /imu, /cmd_vel, /odom, brushes (main, side), vacuum fan, IR sensors. Open source here GitHub - makerspet/proscenic-m6pro: ROS2 robot description for Proscenic M6 Pro · GitHub
- I have had a consumer vacuum cleaner robot torn down, converted to 3D design to experiment with 3D printing it. Open source here GitHub - remakeai/vacuum_cleaner_teardown: Teardown of a home robot vacuum cleaner equipped with LiDAR · GitHub
1 post - 1 participant
ROS Discourse General: AIC Phase 1: How to run custom aic_model service in Flowstate with AIC_ROUTER_ADDR?
Hi Intrinsic / AIC team,
I’m working on AIC Phase 1 in Flowstate and trying to run my participant model as a custom Service instance named exactly aic_model.
The baseline AIC Phase 1 Submission process expects:
- lifecycle service:
/aic_model/change_state - action server:
/insert_cable
I have a local Docker image:
my-solution:phase1_basic_control_ladder
The image works in local Docker Compose when launched with the AIC router environment variables. Its entrypoint requires:
AIC_ROUTER_ADDR
and may require AIC_MODEL_PASSWD if ACL is enabled.
From inspecting the SDK/Flowstate tooling, it looks like the possible path is:
inctl asset install <bundle.tar> --org ... --cluster ...
inctl service add <service_asset_id_version> --cluster ... --name aic_model
I can package the Docker image as a Service asset bundle, but I don’t want to guess the router environment contract.
Questions:
- For a custom Flowstate Service instance named
aic_model, does Flowstate automatically injectAIC_ROUTER_ADDRandAIC_MODEL_PASSWD? - If not, what should
AIC_ROUTER_ADDRbe set to in simulation inside the Flowstate VM? - What is the approved way to provide
AIC_MODEL_PASSWDwithout exposing secrets? - Is
inctl asset install+inctl service add --name aic_modelthe intended local Flowstate testing workflow for AIC Phase 1, or is there another approved way to make the participant model available to the solution?
Thanks!
1 post - 1 participant
ROS Discourse General: Introducing CycloneDDS Insight - Graphical DDS Inspection and Debugging for ROS 2
Introducing CycloneDDS Insight - Graphical DDS Inspection and Debugging for ROS 2.
CycloneDDS Insight is a graphical DDS inspection and debugging tool for ROS 2 and Eclipse Cyclone DDS.
The tool provides visibility into DDS participants, topics, publishers and subscribers, helping users understand system topology, diagnose discovery issues and analyze communication behavior in distributed ROS 2 systems.
Features include:
* Live inspection of DDS entities
* Discovery and communication debugging
* Visualization of communication architectures
* DDS traffic and statistics monitoring
* Support for complex multi-host ROS 2 deployments
CycloneDDS Insight is completely free and open source, making advanced DDS inspection and debugging capabilities accessible to everyone in the ROS 2 community.
Repository:
https://github.com/eclipse-cyclonedds/cyclonedds-insight
Feedback and contributions are welcome.
1 post - 1 participant
ROS Discourse General: Scale Models of ROS robots
A few months ago I had an odd thought (as an occasional modelmaker), has anyone ever made a model of a ROS robot? An AGV, a PR2 to sit on your desk? A Moose? It should be fairly straightforward even, because practically all robot description packages ship a mesh of the robot for rviz which can be fixed up a little and 3D printed to get an exact replica.
I’ve searched quite a bit but couldn’t find anything like that online. So I guess it fell to me to make the first entry.
I got the idea when looking at the ST3045M, the microservo variant of the really practical ST3215 that everyone’s using in SO-ARMs. Something so tiny with full positional and velocity control, low speed torque, odom feedback, and one wire control is like the holy grail for modelmaking.
My first plan was Segway’s Nova Carter, since it’s a fairly aesthetic design, but some miscalculations later I realized it’s way too narrow for it to work with these servos. Clearpath’s Husky or Jackal would work, but then I found Husarion’s Lynx which both looks cooler and the wheel shafts line up almost perfectly when scaled down.
So a few months later, here’s the end result: A 1/5 scale model with most of the capabilities of the real thing, except maybe runtime and a slightly lower scale top speed:
The shell is 3D printed PLA, spray painted, plus some minor weathering with chrome paint, the tires are just off the shelf 1/24 scale crawler wheels with printed hubs. I’ve used double ended LED filaments to make the RGB strips, even the WS2812C is too large at this scale.
I had to modify the servos a bit, sawing off the mounting plates on one side so the shafts would be close enough to the end of the chassis without them poking out. They occupy the entire bottom third:
I was planning to use a Pi Zero 2, but the performance meant it would never be able to run anything useful. The only realistic other option was a CM4 + a drone carrier board to leave me enough space for the other stuff. Expensive but totally worth it imo, since it also has very compact pixhawk connectors and an external antenna plug. I had to take some creative liberties in the rear, extending it out a bit and flattening it so the parts would fit.
(no the tiny estop doesn’t work, sorry
)
As for how I made it run nav2 without a lidar is… well that it does actually have a built in lidar. There’s a Vl53L7CX in the front that behaves a lot like a really garbage stereo camera with only 64 pixels, from which I can extract a horizontal line or two, make some hilarious assumptions and boom a laserscan. Needless to say slam_toolbox recoils in horror unless I disable scan matching, but the wheel odom + BNO085 is actually totally enough to map that way for short periods.
And here are the internals, I’m not really patient enough to make my own PCBs, so it’s just a bunch of dev boards with gratuitous components removed, wrapped in kapton tape and shoved in there.
My enemy throughout the build was heat. I’ve never attempted anything this compact before and with such high power components the second chassis just melted around the CM4. I thought passive cooling will be enough, but even with a heatsink the size of the entire rear end it didn’t really help. So it needs the fan, and extra vents in the wheel wells and the top to help keep the battery cool too. The wheels are ultra soft, which is nice for grip (it can climb up a 30 deg slope out of smooth metal) but they also almost tear off when turning in place on rough surfaces.
The pogo pins in the front are for charging and I have an apriltag dock planned, but I still need to find a usb webcam that looks scale and design a gantry that mounts on top…
I’ve documented most of the setup, since it’s convoluted enough that I’ll forget half of it in two months otherwise, but hopefully it comes in useful for anyone else, there’s some videos there too:
I wouldn’t really recommend anyone to try and recreate it strictly based on that since it’s hardly complete, but I really hope it comes in handy as an inspiration or learning reference. I would just love to see if anyone else has already made something but just never posted it, or if hopefully this gives someone the idea to make something similar. I think a Nova Carter is genuinely doable with geared micro steppers after seeing this thing the other day.
9 posts - 4 participants
ROS Discourse General: ZeroDDS: a pure-Rust RMW for ROS 2 (rc.3), built against 349 real ROS↔DDS pain reports
Full disclosure up front: I work on ZeroDDS, so this is our project, not a neutral review. Sharing it here because it’s specifically aimed at problems this community has been reporting for years, and we’d genuinely like the feedback.
What it is: an alternative RMW for ROS 2, with the whole DDS stack underneath written from scratch in Rust (memory-safe, Apache-2.0, no per-seat license). It speaks native RTPS 2.5 and interoperates with your existing setup: ROS 2 over `rmw_zerodds` talks to ROS 2 over `rmw_cyclonedds` bidirectionally (20/20 in our pub/sub + service tests). It’s a drop-in `RMW_IMPLEMENTATION`, not a fork of your graph.
We didn’t guess at the pain, we catalogued it. Before writing “ROS 2 support” anywhere, we collected 349 real-world ROS↔DDS pain reports from this forum, GitHub and elsewhere, and engineered against the recurring ones:
-
Silent QoS / type mismatches — the classic where two endpoints just never match and nothing is logged. Fixed the keyed/no-key entity-id case, and shipped `zerodds-ros2-shim doctor`, a discovery-independent check that flags the most common WiFi misconfig (multicast-free with no unicast peers) as a hard error instead of a silent no-match.
-
WiFi discovery loss — a single SPDP beacon dropped during 802.11 power-save leaves you at `participants=0`. We send an initial-announcement burst (10×200 ms until matched), like FastDDS’ `initial_announcements`. Verified on a real WiFi rig, not just loopback.
-
Large fleets / WAN — a `multi_robot()` profile: unicast-only discovery, no multicast storm.
-
DDS-Security / SROS2. ZeroDDS consumes SROS2 enclave files (identity/permissions CA, cert, key, governance, permissions) and fails hard on a broken config (no silent downgrade). Caveat for ROS-users: today you point it at the enclave via a ZERODDS_SECURITY_DIR env var, not the standard ROS_SECURITY_KEYSTORE / ROS_SECURITY_ENABLE variables yet. Wiring those up so ros2 security works unmodified is still open.
-
Introspection — `ros2 topic info -v` resolves endpoint GUIDs to node names.
Works with rclpy and rclcpp.
New in rc.3: zero-copy shared memory now works on Windows too (via `CreateFileMapping` + `LockFileEx`), tested on a real Windows runner.
Next (rc.4): a continuous multi-distro live `ros2` smoke as a CI gate across Humble, Iron and Jazzy, so interop is proven on every commit rather than by hand. The `rmw_zerodds` surface itself is code-complete (pub/sub, services, wait-sets, loaned messages, REP-2009 type hash + endpoint info; nothing left `UNSUPPORTED`).
Honest about maturity: it’s a release candidate, not years-hardened. On performance we’re on par with the established stacks across real workloads, not uniformly ahead, and we don’t claim to beat RT-tuned commercial configs. An OMG Vendor-ID is filed but not yet assigned. We are not safety-certified.
Try it:
-
build the rmw layer and run `RMW_IMPLEMENTATION=rmw_zerodds_cpp ros2 …`
-
repo + docs: GitHub - zero-objects/zero-dds: OSS DDS implementation in Rust · GitHub · https://zerodds.de
If you hit a mismatch with your Cyclone/Fast-DDS nodes, or a QoS combination that doesn’t behave, that’s exactly the feedback we want. Tell us where it breaks.
(For the DDS/non-ROS folks who wander in: the same codebase also covers XTypes, DDS-Security, RPC, bridges, seven language bindings, and a full CORBA 3.3 ORB. Happy to go into any of it, but I’ll keep this post ROS-focused.)
1 post - 1 participant




















