Work update: I'm leaving INRIA at the end of this month to join CNRS.

Releasing #Upkie v2 with a live demo tomorrow at #fosdem 2026 🤖 Join us in the Robotics and Simulation devroom (UB2.147, 13:55) if you are interested in open-source robots. Looking forward to the whole day 😃

One week to #fosdem 🤩 FOSDEM is the biggest community-led open-source conference, and it is always a great pleasure to attend: to discover new projects, catch up with the community, and generally for the vibes. There is now a Robotics and Simulation devroom as well. It will take place on […]

#Upkie v2 is here! 🤖 A complete hardware overhaul by Etienne Arlaud and Valentin Tordjman--Levavasseur: - Improved legs with consolidated parts and a wider range of motion - Torso now prints in one pice (down from 7!) with built-in cable management - All […] [Original post on fosstodon.org]

The PlaCo library handles kinematic loop closures 🔄 Frame attachments can be specified in a way compatible with URDF, and a relative position task maintains loop closure during motion. Plus, the documentation is very nice: https://placo.readthedocs.io/en/v0.9.17/kinematics/loop_closures.html

Training a small humanoid robot with reinforcement learning using another robot for reset. by Kaizhe Hu et al. (ToddlerBot Stanford) Project page: robot-trains-robot.github.io

My website (scaron.info) is currently down. I will get it back up as soon as I can, but unfortunately it won't be before next Sunday. I'm sorry for any inconvenience this may cause!

The CoRL 2025 workshop on Open-Source Hardware in the Era of Robot Learning is starting now! You can join the conversation online via live streaming: https://www.youtube.com/live/ZVPIJzF1df4

Tomorrow, 𝗞𝗲𝗻𝘁𝗼 𝗞𝗮𝘄𝗮𝗵𝗮𝗿𝗮𝘇𝘂𝗸𝗮 will present the MEVIUS series of open-source robots: the MEVITA biped, the MEVIUS quadruped and its chimney-climbing extension KLEIYN. What makes these robots special is their use of machined metal components ordered from e-commerce. Their achieve robust locomotion […]

Next Saturday, 𝗧𝗲𝘁𝘀𝘂𝘆𝗮 𝗢𝗴𝗮𝘁𝗮 will present AIREC-Basic, an open robot platform designed for AI developers. His talk will cover the benefits of shifting from proprietary, closed robots to open platforms, such as extensibility and knowledge sharing. It will be accompanied by demonstrations […]

Next Saturday, 𝗔𝗻𝘁𝗼𝗶𝗻𝗲 𝗣𝗶𝗿𝗿𝗼𝗻𝗲 will present Pollen Robotics & Hugging Face's open-source robots, including Reachy Mini, the SO-100 arm, the Amazing Hand and the Open Duck Mini. He will discuss the sim2real challenges of making the Open Duck Mini walk, and how […] [Original post on fosstodon.org]

I have been trying out 𝗨𝗯𝘂𝗻𝘁𝘂 𝗧𝗼𝘂𝗰𝗵 and out of the box the system is pretty neat. Core apps are contributed by the UBports project: https://ubports.com/ With iOS and now Android becoming more locked, their clear app development workflow looks great for, say, open-source robotics projects 🙂 […]

On September 27, 𝗬𝘂𝗸𝗶 𝗡𝗮𝗸𝗮𝗴𝗮𝘄𝗮 will discuss risk assessment and safety design considerations for open-source hardware. She will cover hazard-disclosure practice, the roles of safety standardization and reproducibility for scientific research, and how such standards can facilitate open hardware […]

On September 27, 𝗚𝗿𝗲𝗴𝗼𝗶𝗿𝗲 𝗣𝗮𝘀𝘀𝗮𝘂𝗹𝘁 will present SigmaBan, an open-hardware humanoid robot that has claimed five RoboCup World Championship victories. He will recount the evolution from prototype to champion, covering the integration of ML for perception and […] [Original post on fosstodon.org]

On September 27, 𝗖. 𝗞𝗮𝗿𝗲𝗻 𝗟𝗶𝘂 will share the journey of creating the open-source Stanford ToddlerBot, a fully 3D-printed humanoid robot reproducible for under $6,000. She will dive into key questions on embodied data collection, sim-to-real transfer, and how […] [Original post on fosstodon.org]

On September 27, 𝗞𝗲𝗻𝗻𝗲𝘁𝗵 𝗦𝗵𝗮𝘄 will present current results on democratizing dexterity with the open-source LEAP Hands. He will show how these hands can learn complex, human-like behaviors by leveraging large-scale human motion data and modern simulation […] [Original post on fosstodon.org]

Join us for the 𝗖𝗼𝗥𝗟 𝟮𝟬𝟮𝟱 𝘄𝗼𝗿𝗸𝘀𝗵𝗼𝗽 𝗼𝗻 𝗢𝗽𝗲𝗻-𝗦𝗼𝘂𝗿𝗰𝗲 𝗛𝗮𝗿𝗱𝘄𝗮𝗿𝗲 𝗶𝗻 𝘁𝗵𝗲 𝗘𝗿𝗮 𝗼𝗳 𝗥𝗼𝗯𝗼𝘁 𝗟𝗲𝗮𝗿𝗻𝗶𝗻𝗴! The day will bring together researchers and makers from both academia and the industry to discuss open-source robot design, integration with reinforcement learning […] [Original post on fosstodon.org]

Here is an #Upkie wheeled biped getting up on its own: https://www.youtube.com/watch?v=ZoFQhNnQ62U A combination of reinforcement learning to find an initial trajectory, manual adjustments to transfer to the real robot, and model predictive control for balancing.

Need for Speed or: How I Learned to Stop Worrying About Sample Efficiency Part II of my blog series "Getting SAC to Work on a Massive Parallel Simulator" is out! I've included everything I tried that didn't work (and why Jax PPO was different from PyTorch PPO) araffin.github.io/post/tune-sa...

Testing out implementing inverse dynamics in our new simulator (SIMPLE)

New in SB3 (master branch): to use n-step returns for off-policy algorithms, simply pass `n_steps=3` (it will instantiate a `NStepReplayBuffer` being the scene). Our implementation does not use any for loops, only NumPy vectorised operations at sampling time (so the data container stays the same).

This week I was reminded that nonlinear car-like models are locally controllable, but not their linearization. For instance, the nonlinear car-like model with n trailers is controllable (Robot Motion Planning and Control, p. 77) but its linearization is not (same book, p. 176).

I'm trying out Pixi for the CI of Pink. I appreciate a lot how `pixi run` does locally what will run in GitHub Actions, with the magic of conda-forge to get all dependencies and environments right.

A Lego reaction wheel pendulum that illustrates palatably what state estimation and balancing by PID control look like: https://www.youtube.com/watch?v=WObG2LoSEwQ Note the point where modules get coupled (e.g. PID gains and target variation rate) and there are competing ways to address the […]

One way to balance on wheels by PID control is to cascade two loops: an inner loop commanding wheel velocities from the body tilt error, and an outer loop commanding body tilt from a target ground velocity: https://www.youtube.com/watch?v=k_vYA-xRXyo

I'm adding a test set of differential IK problems to qpbenchmark: https://github.com/qpsolvers/ik_qpbenchmark

New video: model predictive control running on an #Upkie wheeled biped for going around outdoors: https://www.youtube.com/watch?v=pZhLYKkwM1o The shot was thoroughly unplanned, overlays go wherever there was space left 😁

Dealing with stator magnetic saturation: https://jpieper.com/2020/07/31/dealing-with-stator-magnetic-saturation/ explains how the torque-current model in #moteus goes beyond the linear (low torque) regime. A typical great post from Josh Pieper's blog. Oftentimes actuators only model the linear […]

Seen at Humanoids 2024: a new open-source quadruped called MEVIUS. Designed for going outdoors, it is built with T-motor actuators and sheet-metal welded parts that can be ordered on-line. Looking forward to more of those!

h-frac is a research metric proposal. It discounts hyper-authored papers that game the h-index. https://h-frac.org