microduck-stilts

microduck-stilts

Eight MicroDuck forward-walking policies specialized to blend-0.50 stilts from 10 cm to 2.0 m. Every row has its own complete silent 10-second video, ONNX deployment graph, and continuation checkpoint.

The root policy.onnx, manifest.json, and replay.mp4 are convenient aliases for the 10 cm default variant. The height-specific directories remain the authoritative files for all eight variants.

Stilt hardware gallery

<table> <tr> <td align="center"><img src="media/stilts_front.png" width="230" alt="Green 10 cm stilts, front view"><br>_Front</td> <td align="center"><img src="media/stilts_three_quarter.png" width="230" alt="Green 10 cm stilts, three-quarter view"><br>_{Three-quarter}</td> <td align="center"><img src="media/stilts_side.png" width="230" alt="Green 10 cm stilts, side view"><br>_Side</td> <td align="center"><img src="media/printed_stilt.jpg" width="230" alt="Green 3D-printed MicroDuck replacement sole and stilt prototype"><br>_{3D-printed prototype}</td> </tr> </table> <table> <thead> <tr><th>Height</th><th>Full policy rollout</th><th>Files</th></tr> </thead> <tbody> <tr> <td><strong>10 cm</strong><br>_{iteration 2,200}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/10cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="10cm/preview.mp4">Open silent MP4</a></td> <td><a href="10cm/policy.onnx">ONNX</a> · <a href="10cm/checkpoint.pt">checkpoint</a> · <a href="10cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h10p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>15 cm</strong><br>_{iteration 2,400}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/15cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="15cm/preview.mp4">Open silent MP4</a></td> <td><a href="15cm/policy.onnx">ONNX</a> · <a href="15cm/checkpoint.pt">checkpoint</a> · <a href="15cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h15p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>20 cm</strong><br>_{iteration 2,600}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/20cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="20cm/preview.mp4">Open silent MP4</a></td> <td><a href="20cm/policy.onnx">ONNX</a> · <a href="20cm/checkpoint.pt">checkpoint</a> · <a href="20cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h20p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>25 cm</strong><br>_{iteration 2,800}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/25cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="25cm/preview.mp4">Open silent MP4</a></td> <td><a href="25cm/policy.onnx">ONNX</a> · <a href="25cm/checkpoint.pt">checkpoint</a> · <a href="25cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h25p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>50 cm</strong><br>_{iteration 3,400}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/50cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="50cm/preview.mp4">Open silent MP4</a></td> <td><a href="50cm/policy.onnx">ONNX</a> · <a href="50cm/checkpoint.pt">checkpoint</a> · <a href="50cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h50p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>1.0 m</strong><br>_{iteration 4,000}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/100cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="100cm/preview.mp4">Open silent MP4</a></td> <td><a href="100cm/policy.onnx">ONNX</a> · <a href="100cm/checkpoint.pt">checkpoint</a> · <a href="100cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h100p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>1.4 m</strong><br>_{iteration 4,300}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/140cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="140cm/preview.mp4">Open silent MP4</a></td> <td><a href="140cm/policy.onnx">ONNX</a> · <a href="140cm/checkpoint.pt">checkpoint</a> · <a href="140cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h140p0cm.stl">3D print</a></td> </tr> <tr> <td><strong>2.0 m</strong><br>_{iteration 6,500}</td> <td><video src="https://huggingface.co/HannesVonEssen/microduck-stilts/resolve/main/200cm/preview.mp4" width="360" controls autoplay loop muted playsinline preload="metadata"></video><br><a href="200cm/preview.mp4">Open silent MP4</a></td> <td><a href="200cm/policy.onnx">ONNX</a> · <a href="200cm/checkpoint.pt">checkpoint</a> · <a href="200cm/manifest.json">manifest</a> · <a href="https://github.com/Vottivott/microduck-playground/blob/c5fcc50219fef01ac9931d0079c583ccbb29b689/hardware/stilts/generated/release/direct_replacement_pair_b0p50_h200p0cm.stl">3D print</a></td> </tr> </tbody> </table>

All videos show alternating stilt support for the full horizon without reset or auxiliary body contact. These are simulation experiments, not hardware-validated policies. The 50 cm–2.0 m variants are extreme controller research results, not recommendations for monolithic printed hardware.

The simulation mass law is 12 g + 1 g/cm per stilt. The 10 cm policy was trained at 22 g per stilt; the prototype slicer estimate is about 29 g per stilt. The unchanged actor survived an initial 64-environment, 10-second simulation battery at 29 g, but broader mass-randomized continuation and tethered hardware testing are still required. See the exact mass audit.

Matching geometry and source

Training code, the executed curriculum, and left/right/paired STLs for every released height are in Vottivott/microduck-playground at commit c5fcc50.

• Exact released STL index
• Executed training lineage
• Parametric generator

Run one policy

git clone https://github.com/Vottivott/microduck-playground.git
cd microduck-playground
git checkout c5fcc50219fef01ac9931d0079c583ccbb29b689
uv sync

hf download HannesVonEssen/microduck-stilts 25cm/policy.onnx config.json \
  --local-dir policies/stilts

MICRODUCK_STILT_HEIGHT_CM=25 MICRODUCK_STILT_BLEND=0.5 \
  uv run python scripts/infer_policy.py \
    --walking policies/stilts/25cm/policy.onnx \
    --new-cmd-obs --lin-vel-x 0.15

Continue training

Each checkpoint.pt preserves the exact released actor and normalizer. Because the original stilt critic and optimizer snapshots were not retained, it uses a fresh compatible critic scaffold, empty optimizer moments, 1e-5 learning rate, and 0.1 exploration standard deviation. It is an actor-exact warm start, not the original full PPO state.

mkdir -p logs/rsl_rl/stilt_locomotion/release-25cm
cp policies/stilts/25cm/checkpoint.pt \
  logs/rsl_rl/stilt_locomotion/release-25cm/model_2800.pt

MICRODUCK_STILT_HEIGHT_CM=25 MICRODUCK_STILT_BLEND=0.5 \
  uv run train Mjlab-Stilt-Flat-MicroDuck \
    --agent.resume True \
    --agent.load-run release-25cm \
    --agent.load-checkpoint model_2800.pt \
    --agent.max-iterations 100

See TRAINING.md for the full lineage, checkpoint caveat, and promotion procedure. PyTorch checkpoints use pickle internally; load them only from a repository and revision you trust.

Runtime contract

• input: obs, float32 [1, 61]
• output: actions, float32 [1, 14]
• control rate: 50 Hz
• action scale: 1.0 rad around MicroDuck HOME joint pose
• observation normalizer: baked into each ONNX
• command: twist=[0.15, 0, 0], zero head/body commands
• morphology: matching height, blend 0.50, 17 × 22 mm rounded tips

The 3.0 m demonstration is intentionally absent: it was a zero-shot failure of the unchanged 2.0 m policy, not a separately trained model.

<a href="https://hfviewer.com/HannesVonEssen/microduck-stilts?utm_source=huggingface&amp;utm_medium=embedded_model_card&amp;utm_campaign=HannesVonEssen__microduck-stilts_card&amp;utm_content=embedded_card_open_viewer&amp;from=embedded-model-card" target="_blank" rel="noopener"> <img src="https://hfviewer.com/api/card.svg?source=HannesVonEssen%2Fmicroduck-stilts&amp;granularity=auto&amp;v=20260902-action-contract-r2" alt="Architecture graph for HannesVonEssen/microduck-stilts. Open in hfviewer" width="100%" /> </a>