Action-Aligned Latent Planning for Versatile Humanoid Loco-Manipulation
Organizations: Amazon FAR. · Carnegie Mellon University. · Stanford University.
Abstract
Learning a single perceptive policy for diverse humanoid loco-manipulation requires unifying high-level task decisions without losing the state-dependent physical responses that make each interaction succeed. This makes the representation between high-level planning and whole-body control critical: kinematic or contact targets provide compact abstractions but do not directly encode interaction-specific control responses, while directly predicting low-level actions requires the planner to model high-frequency closed-loop feedback. We propose FIBER, a framework that uses the executable latent space of a frozen behavioral foundation model (BFM) as a shared planning representation for heterogeneous interaction skills. Our latent policy projection (LPP) maps independently acquired task-specific policies into this representation by identifying latent commands whose induced actions match their local control responses, enabling lower-rate planning while retaining the BFM's high-frequency state feedback. After projection, we aggregate closed-loop latent rollouts from all skills and train a single perceptive flow planner entirely offline. We further introduce AH-BFM, an adaptive-horizon BFM trained with multi-gamma forward-backward (FB) learning to support both precise control and temporally extended whole-body behavior. We evaluate FIBER on box pickup, door opening, and object grasping in simulation and on a real Unitree G1 humanoid. Across 128 diverse variations per task in simulation, FIBER achieves 42.0% mean success, more than tripling projected latent replay (11.6%) and substantially outperforming kinematic planning (3.5%). Real-world experiments further demonstrate sim-to-real transfer, skill chaining, and conditional steering through the same unified planner.
Figures & tables
| Method | Pickup Box | Open Door | Grasp Object | Mean | ||
| w/ appr. | w/o appr. | w/ appr. | w/o appr. | |||
| Task-specific policies | ||||||
| Expert Policy † | 100.0 0.0 | 90.8 0.5 | 89.3 0.2 | 97.9 0.8 | 97.0 0.8 | 95.4 |
| lpp w/ SONIC [ 34 ] † | 0.0 0.0 | 0.0 0.0 | 83.1 0.7 | 88.1 0.6 | 5.1 0.7 | 29.4 |
| LPP w/ Fixed- BFM † | 75.4 0.2 | 80.2 1.3 | 61.8 1.9 | 72.4 0.7 | 69.3 1.2 | 68.8 |
| lpp w/ AH-BFM † | 81.9 0.9 | 87.4 2.4 | 83.5 1.8 | 97.3 0.4 | 52.9 2.1 | 72.8 |
| Method | Pickup Box | Open Door | Grasp Object | Mean |
| Fiber | 6/10 | 4/10 | 2/10 | 40% |
| Method | Joint-MAE | BE-EMD | |||
| 0.2 s | 0.5 s | 1 s | 2 s | ||
| SONIC [ 34 ] | 0.1315 | – | – | – | – |
| BFM | 0.1107 | 0.038 | 0.200 | 0.495 | 0.792 |
| BFM | 0.1327 | 0.048 | 0.213 | 0.451 | 0.601 |
| AH-BFM | 0.1020 | 0.049 | 0.195 | 0.422 | 0.590 |
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
| Component | Hidden width | Hidden layers |
| Body actor | 2048 | 6 |
| Forward representation | 2048 | 6 |
| Critics | 2048 | 6 |
| Backward encoder | 1024 | 1 |
| Motion discriminator | 1024 | 3 |
| Executable latent dimension | 256 | |
| Parameter | Value |
| Forward-map learning rate | |
| Backward-map learning rate | |
| Actor / critic learning rate | |
| Discriminator learning rate | |
| Minibatch size | 1024 |
| Training updates | 100,000 |
| Parameter | Motion expert | SF adapter |
| Rollout steps / environment | 32 | 32 |
| Learning rate | ||
| Optimization epochs | 3 | 5 |
| Minibatches / rollout | 8 | 4 |
| PPO clipping parameter | 0.2 | 0.2 |
| Discount | 0.99 | 0.99 |
| Parameter | Value |
| Optimizer | AdamW |
| Learning rate | |
| Weight decay | |
| Gradient-norm limit | 1 |
| Minibatches / rollout | 4 |
| Optimization passes / rollout | 5 |
| Component or parameter | Configuration | Component or parameter | Configuration |
| Executable body latent | Transformer width / latent blocks | 1024 / 16 | |
| Prediction horizon | s | Attention heads / per-head width | 8 / 128 |
| Body / optional hand state | 58 / 14 | Feed-forward expansion / activation | 4 / GELU |
| Optional hand target | 14 per latent step | Attention / feed-forward dropout | 0 / 0.2 |
| Depth image / patch shape | / | Conditioning registers | 8 |
| Depth range / spatial tokens | – m / 192 | Flow-time embedding scale | 1000 |
| Parameter | Value |
| Optimizer | AdamW |
| Learning rate | |
| Weight decay | |
| Warm-up updates | 100 |
| Post-warm-up schedule | Constant |
| Batch size | 256 |
| Task | Variation | Evaluation range |
| Box pickup | Box geometry, placement, and mass | Base size cm, independently scaled by and , yielding sizes from cm to cm. Boxes are placed either on the ground or on supports – m high, with mass sampled from – kg. |
| Door opening | Door geometry and handle placement | Door width – m and height – m. Handle height is – m above the ground, with lateral inset – m. |
| Object grasping | Object identity and shape | distinct object instances are evaluated with four takes per object ( episodes total), selected through teacher-feasibility screening from object instances and usable demonstrations. |
Humanoid Loco-Manipulation
Humanoid loco-manipulation studies how robots coordinate walking, balance, and whole-body interaction to move and handle objects.
See all 86 papers