Cracking Mobile Manipulation: From Failure Diagnosis to Agentic Robot System
Organizations: School of Intelligence Science and Technology, Peking University · State Key Laboratory of General Artificial Intelligence, Peking University · Alibaba DAMO Academy, Alibaba Group · Institute of Automation, Chinese Academy of Sciences · Tsinghua University · University of Technology Sydney · University of Liverpool
Abstract
Recent vision-language-action (VLA) models have shown strong performance on local robot manipulation, yet their success does not readily translate to long-horizon mobile manipulation. In our experiments, a pretrained subtask VLA achieves 80% success rate on atomic manipulation tasks but only 19% when these skills are composed into mobile manipulation. We argue that this gap stems from failures across the execution process rather than from local manipulation capability alone. To uncover these bottlenecks, we systematically diagnose failures in long-horizon mobile manipulation and identify three dominant regimes: task planning, navigation and base positioning, and local manipulation. Based on this diagnosis, we develop failure-guided agentic intervention that augments a fixed subtask VLA with demonstration-based planning guidance, adaptive visual memory, accessibility-aware base adjustment, and local end-effector adjustment. On RoboCasa365, these interventions progressively improve task success from 19% to 47%, with the finalized system reaching 49% on held-out episode seeds, compared with 18% for the baseline. The same design improves performance from 14% to 37% on BEHAVIOR-1K and from 5/20 to 13/20 on real-robot tasks. These results suggest that reliable mobile manipulation can be advanced by diagnosing and intervening on the current bottleneck, rather than uniformly scaling the underlying policy. Our code will be released at https://github.com/PKU-VaLuE-Lab/Cracking-Mobile-Manipulation.git.
Figures & tables
| Type | Method | Development (%) | Held-out (%) |
|---|---|---|---|
| VLA | ( Black et al., 2025b ) | 2.0 | 2.0 |
| ( Black et al., 2025a ) | 3.0 | 4.0 | |
| GR00T N1.6 ( NVIDIA, 2025b ) | 7.0 | 8.0 | |
| GR00T N1.5 ( NVIDIA, 2025a ) | 8.0 | 9.0 | |
| RLDX-1 ( Kim et al., 2026a ) | 15.0 | 14.0 | |
| Xiaomi Robotics 1 ( Xiaomi Robotics Team et al., 2026 ) | 44.0 | 45.0 |
Appendix figures & tables18 assets
Supplementary material from the paper’s appendix.
Appendix
| Setting | Value |
|---|---|
| VLM backbone | Qwen3-VL-4B-Instruct |
| Visual encoder | DINOv2 ViT-S/14 |
| Action model | DiT-B |
| Image resolution | |
| State dimension | 16 |
| Action dimension | 12 |
| Method | Batch Size | Training Steps |
|---|---|---|
| 64 | 75,000 | |
| 64 | 75,000 | |
| GR00T N1.5 | 128 | 120,000 |
| GR00T N1.6 | 128 | 120,000 |
| RLDX-1 | 192 | 250,000 |
| Xiaomi Robotics 1 | 512 | 120,000 |
| Failure Category | Episodes | Unanimous |
|---|---|---|
| Task planning | 7 | 6 |
| Navigation and base positioning | 8 | 7 |
| Manipulation | 15 | 13 |
| Total | 30 | 26 |
| Fine-grained failure category | Episodes | Unanimous |
|---|---|---|
| Placement target or receptacle assignment | 4 | 3 |
| Subtask ordering | 3 | 2 |
| Ineffective approach or poor base positioning | 4 | 4 |
| Collision, path blockage, or stalled navigation | 3 | 2 |
| Unsuitable base orientation | 2 | 2 |
| Incorrect object placement | 5 | 4 |
| Parameter | Value |
|---|---|
| Adaptive visual memory | |
| Maximum candidate frames | 256 |
| Retrieved frames ( ) | 16 |
| Recall model | Qwen3.8-27B |
| Input image resolution | |
| Geometric skills | |
| Comparison | Success (%) | (pp) | 95% CI (pp) | McNemar | ||
|---|---|---|---|---|---|---|
| Baseline +Demo | 19 25 | +6 | 8 | 2 | [0, 12] | 0.109 |
| +Demo +Memory | 25 29 | +4 | 7 | 3 | [-2, 10] | 0.344 |
| +Memory +Base | 29 40 | +11 | 15 | 4 | [3, 19] | 0.019 |
| +Base +EEF | 40 47 | +7 | 10 | 3 | [0, 14] | 0.092 |
| Baseline Full | 19 47 | +28 | 30 | 2 | [18, 38] |
| Added intervention | Recovered | Planning | Nav./Base | Manip. |
|---|---|---|---|---|
| Skill library | 8 | 5 | 1 | 2 |
| Adaptive visual memory | 7 | 4 | 1 | 2 |
| Base adjustment | 15 | 0 | 11 | 4 |
| End-effector adjustment | 10 | 0 | 1 | 9 |
| Baseline Full | Success | Planning | Nav./Base | Manip. | Total |
|---|---|---|---|---|---|
| Success | 17 | 0 | 1 | 1 | 19 |
| Planning | 9 | 1 | 1 | 6 | 17 |
| Nav./Base | 12 | 0 | 3 | 6 | 21 |
| Manipulation | 9 | 0 | 0 | 34 | 43 |
| Total | 47 | 1 | 5 | 47 | 100 |
| Task horizon | # Tasks | Baseline | Full system | (pp) |
|---|---|---|---|---|
| 2–4 subtasks | 13 | 15/65 (23.1%) | 35/65 (53.8%) | +30.7 |
| 5–15 subtasks | 7 | 4/35 (11.4%) | 12/35 (34.3%) | +22.9 |
| Overall | 20 | 19/100 (19.0%) | 47/100 (47.0%) | +28.0 |
| Method | Storage Box Transport | Table Service | Overall |
|---|---|---|---|
| (end-to-end VLA) | 2/10 | 2/10 | 4/20 |
| Agentic baseline | 2/10 | 3/10 | 5/20 |
| Full system | 6/10 | 7/10 | 13/20 |
| Configuration | Task Success Rate(%) | from Full (pp) |
|---|---|---|
| Full system | 47.0 | – |
| Skill library | 39.0 | -8.0 |
| Adaptive visual memory | 41.0 | -6.0 |
| Base adjustment | 35.0 | -12.0 |
| End-effector adjustment | 40.0 | -7.0 |
| Memory Access | Uniform | Relevance-based |
|---|---|---|
| Every turn | 40.0 | 45.0 |
| Planner-triggered | 44.0 | 47.0 |