Hardware verifiedroller skatev1.0.0Apache-2.0

Roller Blade Crouch Glide

Aerodynamic tuck crouch maneuver while coasting on roller skates, lowering center of gravity for high-speed stability.

About this behavior

A 3.5-second one-shot gesture on rollers. Driven by phase encoding [cos(2pi*t), sin(2pi*t), 0] in the command slots (matching ground-pick architecture). The duck folds its legs, lowers its center of mass near the wheel axles, and smoothly returns to an upright skating tuck.

Runtime contract

61-dimension input · 14 joint targets · 50 Hz

Show details

50 Hz / 4×slot: rollers

Observation vector61 dimensions · normalizer baked in

Proprioception48D

Positions, velocities, previous actions, gravity, and gyro.

Twist command3D

Forward, lateral, and yaw velocity intent.

Head pose4D

Neck and head orientation targets.

Body pose6D

Six-axis torso offset command.

Action targetsscale: 1×

Left leg5 joints

hip yaw · hip roll · hip pitch · knee · ankle

Neck & head4 joints

neck pitch · head pitch · yaw · roll

Right leg5 joints

hip yaw · hip roll · hip pitch · knee · ankle

Actuator model: Dynamixel XL330 (BAM M6 voltage control law). The beak motor is separate from this fixed locomotion action space.

Verification

Status: Hardware verified
Evidence: Verified on physical MicroDuck on roller wheels performing controlled crouch-glide cycles.
Target hardware: MicroDuck v1 + Roller Skate Blades
Simulation: mjlab (MuJoCo Warp) at 50 Hz
Note: Cycle duration: 3.5 seconds (period 5.0s, end phase 0.7).

Compatibility

Robot model: microduck-rollers
MJCF model: robot_allcollisions_rollers.xml
Terrain: flat
Required accessories: roller skates

Run it on your duck

Use the canonical model and this policy slot to try the behavior locally.

slot: rollers

Try the simulation first. Hardware testing assumes a matching Microduck, clear space, and a safe surface. uDuck does not guarantee that a community policy is safe to run.

Deployment stepsShow instructions

1 Download the ONNX model BEST_roller_crouch.onnx

curl -L "https://huggingface.co/spaces/pollen-robotics/microduck-simulator/resolve/main/app/public/policies/BEST_roller_crouch.onnx" -o "/opt/robot/policies/BEST_roller_crouch.onnx"

2 Add the policy to robotd

[policy]
roller_crouch = "/opt/robot/policies/BEST_roller_crouch.onnx"

3 Restart the control loop

sudo systemctl restart robotd
robotctl health

⌁ Try it in simulation

uv run scripts/infer_policy.py --walking BEST_roller.onnx --new-cmd-obs

Sources

Upstream repositorypollen-robotics/microduck Training codeMjlab-RollerCrouch-Flat-MicroDuck Interactive simulatorhttps://huggingface.co/spaces/pollen-robotics/microduck-simulator