CLARO: Clutter Aware Robot Orchestrator for Open-Vocabulary Grasping using VLM Agents
Organizations: New York University
Abstract
Robots that follow natural-language instructions unlock a wide range of autonomous applications in households, warehouses, and labs. Real-world environments are diverse and often heavily cluttered, requiring robots to plan over multiple steps, act, and replan as they work toward a goal. We present CLARO (CLutter-Aware Robot Orchestrator), a VLM agent that orchestrates a set of perception and manipulation skills: open-vocabulary object detection, segmentation, 6-DoF grasping, and non-prehensile pushing to locate and retrieve a language-specified target in clutter. CLARO maintains a memory of its past actions to support long-horizon execution, and emits manipulation targets (grasp poses/3D waypoints) allowing transfer across robot arms without task-specific training. We evaluate CLARO against a range of methods on a dynamic simulation environment and standard image-based benchmarks, demonstrating strong generalization across object classes, lighting, and clutter levels. CLARO attains an average success rate of 89.1%, a relative improvement of over 16% on the strongest competing method in high cluttered scenes. We further analyze performance along grounding and grasping axes to characterize where each method succeeds and fails. Finally, we deploy CLARO on a robot arm across diverse cluttered scenes, achieving a success rate of 88.8%, and demonstrating strong sim2real generalizability.
Figures & tables
| Method | Grasp Modality | Open- Vocab. | Closed-Loop Planning | Long-Term Memory | Non-Prehensile Manip. | Cross-Arm Deploy. |
|---|---|---|---|---|---|---|
| Referring Grasp Synthesis methods | ||||||
| CROG [ 30 ] | 4-DoF | ✗ | ✗ | ✗ | ✗ | ✓ |
| MapleGrasp [ 2 ] | 6-DoF | ✗ | ✗ | ✗ | ✗ | ✓ |
| UnoGrasp [ 13 ] | 6-DoF | ✗ | ✓ | ✗ | ✗ | ✓ |
| Language-agnostic grasp generation | ||||||
| GraspGen [ 19 ] | 6-DoF | ✗ | ✗ | ✗ | ✗ | ✓ |
| Grounding SR. (%) | Grasping SR. (%) | Task SR. (%) | Action Steps | |||||
|---|---|---|---|---|---|---|---|---|
| Method | Low | High | Low | High | Low | High | Low | High |
| GraspGen* [ 19 ] | 36.2 | 35.4 | 48.8 | 42.2 | 19.2 | 9.4 | 8.8 | 9.2 |
| GraspMAS [ 20 ] | 62.8 | 55.0 | 29.2 | 25.8 | 27.2 | 16.7 | 1.3 | 1.1 |
| UnoGrasp [ 13 ] | 52.7 | 46.1 | 32.5 | 18.8 | 34.2 | 23.8 | 8.7 | 9.2 |
| ThinkGrasp [ 23 ] | 73.8 | 68.8 | 34.5 | 19.2 | 76.2 | 75.3 | 5.4 | 6.4 |
| OWG [ 29 ] | 76.1 | 71.4 | 52.5 | 26.9 | 83.3 | 76.3 | 2.7 | 3.9 |
| Method | OCID-VLG [ 30 ] | GraspAnything++ [ 31 ] |
|---|---|---|
| OWG [ 29 ] | 53.1 | 42.9 |
| ViperGPT [ 27 ] | 44.0 | 57.0 |
| ThinkGrasp [ 23 ] | 48.5 | 38.4 |
| GraspMAS [ 20 ] | 62.0 | 68.0 |
| CLARO (ours) | 67.2 | 76.5 |
| Task SR (%) | Action Steps | |||
| Variant | Low | High | Low | High |
| CLARO (full) | 89.5 | 88.6 | 3.0 | 4.9 |
| w/o push tool | 77.4 | 60.0 | 6.6 | 7.5 |
| w/o long-term memory | 71.2 | 52.9 | 1.9 | 3.8 |
| w/o closed-loop replanning | 74.9 | 56.6 | 3.1 | 4.1 |
| w/o VLM based planning | 62.5 | 54.8 | 5.4 | 6.2 |
| Task SR (%) | Action Steps | |||
|---|---|---|---|---|
| Method | Low | High | Low | High |
| OWG [ 29 ] | 67.5 35.4 | 22.5 32.8 | 3.4 1.2 | 4.6 0.9 |
| ThinkGrasp [ 23 ] | 70.0 33.8 | 50.0 35.5 | 3.2 1.3 | 4.3 1.1 |
| CLARO (ours) | 97.5 7.1 | 80.0 23.9 | 3.3 1.1 | 5.4 1.8 |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Method | VLM | Grounding | Grasping |
|---|---|---|---|
| CLARO (Ours) | Gemini 3.1 Pro | SAM3 | GraspGen 6-DOF |
| OWG | GPT-5.4 | SAM3 | GR-ConvNet 4-DOF |
| ThinkGrasp | GPT-5.4 | LangSAM | GraspNet 6-DOF |
| GraspMAS | GPT-5.4 | VLPart + SAM3 | RAGT 4-DOF |
| UnoGrasp | UnoGrasp (fine-tuned) | SAM3 | GraspNet 6-DOF |
| RoboDexVLM | GPT-5.4 | LangSAM | AnyGrasp 6-DOF |
| GPT 5.4 | Gemini 3.1 Pro | |||
|---|---|---|---|---|
| Task SR (%) | Low | High | Low | High |
| OWG | 83.3 | 76.3 | 55.2 | 49.8 |
| ThinkGrasp | 76.2 | 75.3 | 80.8 | 78.2 |
| Task SR (%) | Action Steps | |||
|---|---|---|---|---|
| CLARO Memory Variant | Low | High | Low | High |
| Full (default) | 89.5 | 88.6 | 3.0 | 4.9 |
| Text-Only | 86.8 | 80.4 | 3.1 | 5.2 |
| Images-Only | 76.3 | 61.7 | 2.4 | 4.0 |
| Actions-Only | 73.1 | 55.8 | 2.1 | 3.9 |
| No-Memory | 71.2 | 52.9 | 1.9 | 3.8 |
| Failure source | Count | Fraction |
|---|---|---|
| Perception / SAM-mask quality | 10 | 19.61% |
| Grasp generation or execution | 22 | 43.14% |
| Push planning or execution | 19 | 37.25% |
| Total failure events | 51 | 100.00% |
| Call Type | Mean | Median | Cost Share |
|---|---|---|---|
| Planner | 21.0 | 17 | 74% |
| survey_scene | 13.8 | 6 | 26% |
| Total model calls | 34.8 | 23 | — |
| API cost / episode | $0.13 | $0.09 | — |
| Method | VLM calls / ep. | API cost / ep. |
|---|---|---|
| OWG | 6.2 | $0.023 |
| ThinkGrasp | 5.6 | $0.021 |
| CLARO (full) | 34.8 | $0.13 |
| CLARO ( Text-Only memory) | 35.2 | $0.052 |
| Grounding SR (%) | Task SR (%) | |||
|---|---|---|---|---|
| Method | Direct | Indirect | Direct | Indirect |
| ThinkGrasp | 71.2 | 64.0 | 75.6 | 66.6 |
| OWG | 73.6 | 61.8 | 79.4 | 70.2 |
| CLARO | 87.2 | 83.2 | 89.0 | 85.4 |
| Category | Total |
|---|---|
| Toys & Figurines | 86 |
| Bottles & Cans | 37 |
| Boxes & Packaging | 56 |
| Electronics | 28 |
| Footwear | 49 |
| Kitchenware | 27 |
| Contextual cue in planner’s reasoning | push | grasp |
|---|---|---|
| Target/occluder hidden | ||
| Insufficient clearance around target | ||
| Object needs reorientation for stable grasp | ||
| Object obstructs the target directly | ||
| Target object visible and reachable |
| judgments | rating (%) | |||
|---|---|---|---|---|
| action | % ( ) | pos | neu | neg |
| grasp | 68.7 (206) | 88.8 | 5.9 | 5.3 |
| push | 31.3 (94) | 77.7 | 19.1 | 3.2 |
| overall | 100.0 (300) | 85.3 | 10.0 | 4.7 |
Robotic Grasping
Robotic grasping studies how robots perceive, plan, and execute stable, task-appropriate contacts with objects across varied shapes and conditions.
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