Cognition to Control - Multi-Agent Learning for Human-Humanoid Collaborative Transport
Organizations: University of Texas at Arlington. · Carnegie Mellon University
Abstract
Full-stack human-robot collaboration (HRC) can become brittle when replacing a planner, partner model, coordination policy, or controller changes the physical meaning of cross-layer signals. We introduce C2C, an object-centric cognition-to-control architecture that preserves these meanings through physical contracts. Rather than standardizing individual modules, C2C standardizes the physical semantics exchanged between them: task intent is represented by a geometrically verified payload path, partner information by a source-independent physical state, learned coordination by bounded 11-D task-space commands, and robot-specific feasibility remains inside whole-body control (WBC). The reference system combines a vision-language model with deterministic geometric verification and multi-agent reinforcement learning (MARL) for partner-aware coordination. Across nine transport scenarios, adaptive MARL variants achieve 77.1-82.1% mean success under unchanged interfaces, compared with 56.5% for a scripted-partner reference. The same contracts further support neural and interpretable hard-tree actors, two- and three-carrier teams, and simulated-to-human partner substitution. Physical Unitree G1-human tests achieve 100% success in spatially confined transport and 80% in super-long-object handling, while a three-carrier system with two G1 humanoids and one human validates the same interface structure on hardware. Together, these results show that C2C converts a tightly coupled HRC stack into a plug-compatible system in which key components can change without redefining the physical collaboration task.
Figures & tables
| Component | Size | Description |
| Observation space ( ) | ||
| Global guidance | 10 | 5 anchors (relative planar) |
| Self state | 13 | Pose/velocity, CoM, torso, wrists |
| Partner state | 13 | Measured/policy partner |
| Object geometry | 18 | 4 corners, CoM pose/velocity |
| Contact | 4 | 4 binary contact indicators |
| Category | Scenario | Robot-script | HAPPO | HATRPO | PPO+PCGrad | Mean gain |
|---|---|---|---|---|---|---|
| OSP | : Alignment | 65.4 7.2 | 83.6 5.3 | 87.9 4.5 | 87.7 3.8 | +32.1% |
| : Turnaround | 60.1 8.5 | 77.6 6.3 | 81.5 5.5 | 83.6 4.8 | +34.6% | |
| : Corner entry | 58.2 9.1 | 72.7 7.0 | 75.3 6.0 | 77.8 5.3 | +29.3% | |
| SCT | : Narrow gate | 59.2 9.0 | 80.1 4.8 | 83.4 4.3 | 88.6 3.5 | +42.0% |
| : S-shaped path | 57.5 8.8 | 76.3 5.8 | 82.1 5.0 | 80.6 4.5 | +38.6% | |
| : U-shaped path | 55.6 9.5 | 75.7 6.5 | 79.2 5.3 | 81.3 4.8 | +41.6% |
| Parameter | Value | Parameter | Value |
|---|---|---|---|
| Learning rate | Hidden layers | [256,256,128] | |
| Epochs/update | 10 | Activation | ReLU |
| Minibatches | 16 | Initialization | Orthogonal |
| Entropy weight | 0.01 | Optimizer | Adam |
| Discount factor | 0.99 | Weight decay | |
| GAE factor | 0.95 | Gradient clip | 10.0 |
| Axis | Substitution | Invariant interface | Evidence |
|---|---|---|---|
| Cognition | VLM deterministic fallback | Verified payload path | Same downstream path contract |
| Coordination | HAPPO / HATRPO / PPO+PCGrad | Observation, 11-D action, reward, WBC | SR: 77.1 / 80.8 / 82.1% |
| Partner | Simulated carrier human | Partner-state fields and robot action | Physical SR: 100 / 100 / 80% |
| Policy | MLP hard tree | N=3 adapter, action, reward, WBC | SR: 74.7 70.3% |
| Team size | Two three carriers | Guidance, action semantics, reward, WBC | SR: 77.1 74.7% |
| Task | Robot-script IPPO | PPO+PCGrad | ||||
|---|---|---|---|---|---|---|
| SR | Tilt ( ∘ /s) | Time (s) | SR | Tilt ( ∘ /s) | Time (s) | |
| OSP | 100% | – | 74.2 | 100% | – | 65.2 |
| SCT | 40% | 3.2 | 101.6 | 100% | 2.4 | 81.5 |
| SLH | 40% | 3.6 | 113.6 | 80% | 2.7 | 86.9 |