Advancing Multi-Robot Networks via MLLM-Driven Sensing, Communication, and Computation: A Comprehensive Survey
Organizations: Department of Electrical and Computer Engineering, Seoul National University, Seoul, South Korea · Department of Electrical and Computer Engineering, Ajou University, Suwon, South Korea · Department of Intelligent Software, College of Computing and Informatics, Sungkyunkwan University, Suwon, South Korea · Department of Computer Science and Engineering, Korea University, Seoul, South Korea ·
Abstract
Imagine advanced humanoid robots, powered by multimodal large language models (MLLMs), coordinating missions across industries like warehouse logistics, manufacturing, and safety rescue. While individual robots show local autonomy, realistic tasks demand coordination among multiple agents sharing vast streams of sensor data. Communication is indispensable, yet transmitting comprehensive data can overwhelm networks, especially when a system-level orchestrator or cloud-based MLLM fuses multimodal inputs for route planning or anomaly detection. These tasks are often initiated by high-level natural language instructions. This intent serves as a filter for resource optimization: by understanding the goal via MLLMs, the system can selectively activate relevant sensing modalities, dynamically allocate bandwidth, and determine computation placement. Thus, R2X is fundamentally an intent-to-resource orchestration problem where sensing, communication, and computation are jointly optimized to maximize task-level success under resource constraints. This survey examines how integrated design paves the way for multi-robot coordination under MLLM guidance. We review state-of-the-art sensing modalities, communication strategies, and computing approaches, highlighting how reasoning is split between on-device models and powerful edge/cloud servers. We present four end-to-end demonstrations (sense -> communicate -> compute -> act): (i) digital-twin warehouse navigation with predictive link context, (ii) mobility-driven proactive MCS control, (iii) a FollowMe robot with a semantic-sensing switch, and (iv) real-hardware open-vocabulary trash sorting via edge-assisted MLLM grounding. We emphasize system-level metrics -- payload, latency, and success -- to show why R2X orchestration outperforms purely on-device baselines.
Figures & tables
| Paradigm | Defining scope and features | R2R comm. protocol | Ultra-low latency support | Consideration of multiple robot collab. | Task-central comm. reqs. design | Integrated sensing/ computing/ comm. design | Inclusion of LLM-Based AI synergy | Relevant surveys |
| Robot collaboration | Emphasizes multi-robot synergy through shared perception and distributed planning, yet rarely integrates underlying communication protocols or edge/cloud offloading mechanisms. | X | X | O | X | X | X | [ 9 , 10 , 11 , 12 ] |
| V2X | Concentrates on vehicle-to-everything links for low-latency road safety and traffic coordination, lacking a broader focus on multi-robot contexts or advanced AI-driven orchestration. | X | O | X | X | X | X | [ 5 ] |
| M2M | A device-centric communication protocol for automated IoT interactions, including R2R, yet generally omits goal-oriented design or large-model–assisted collaboration. | O | X | X | X | X | X | [ 3 , 4 ] |
| URLLC | Promises ultra-reliable, sub-ms network links for mission-critical 5G/6G, but seldom integrates multi-robot perception or large-scale AI inference into the communication structure. | X | O | X | X | X | X | [ 6 , 7 , 8 ] |
| R2X (Proposed) | Offers a full-stack paradigm coupling LLM-based feature vector encoding, multimodal sensing (incl. emergency audio/visual cues), edge/cloud resource management, and multi-robot collaboration from physical-layer protocols to high-level orchestration, enabling intent-to-resource orchestration from language goals to sensing/communication/computation decisions. | O | O | O | O | O | O | This work. |
| Topic | Method | Ref. | Key Contribution |
| Multi-modal Sensing | MUTEX | [ 60 ] | LMM equipped with a Transformer-based cross-modal fusion module capable of processing six modalities. Introduces a two-stage training procedure and a multi-modal training dataset collected from both simulated and real-world environments. |
| Matcha | [ 61 ] | Robotic planning system that actively collects information from multi-modal sensors (vision, sound, haptics) by performing epistemic actions. The LMM reasons over the information obtained from such actions and plans the main task execution. | |
| REFLECT | [ 59 ] | Robot failure explanation system based on the summarization of the robot experiences, represented as hierarchically structured multi-sensory data. The summarization is used to develop a natural language behavior explanation system and to improve the model’s correction ability. | |
| MultiPLY | [ 62 ] | Embodied LMM that utilizes encoded sensor representations obtained from diverse interactive 3D environments. Sensors include visual, audio, tactile, and thermal information. A large-scale multi-sensor dataset, Multisensory Universe , is also introduced. | |
| Language-based Task & Env. Underst. | PaLM-E | [ 54 ] | Embodied LMM that takes text-based task instructions for various robot tasks, including perception, visually-grounded question-answering, and planning. PaLM-E leverages a pre-trained LLM as the initial state and adapts the model using robot-aware training data. |
| CLIPORT | [ 57 ] | CLIP-based language conditioning model for vision-based robot control. The model utilizes semantic (RGB) and spatial (RGB-D) visual data using separate submodules, both conditioned on the CLIP text embedding. |
| Robot Operating System (ROS) | Vision Language Action Model (VLA) | |
| Purpose | • Middleware framework for robotic system development. • System-level integration of hardware and software for robots. | • AI-driven reasoning and perception. • High-level reasoning, task abstraction, and perception-to-action mappings. |
| Example | • ROS1 [ 70 ] , ROS2 [ 76 ] | • SayCan [ 55 ] , PaLM-E [ 54 ] , RT-1 [ 14 ] , RT-2 [ 15 ] , OpenVLA [ 65 ] , LLARVA [ 49 ] , [ 50 ] |
| Communication & Computing Aspect | • Publish-subscribe model, standardized messaging, widely used. • Distributed processes, moderate hardware requirements. | • High-bandwidth data handling for large AI models, integrates advanced inference frameworks. • Transformer-based deep learning, requires substantial computational resources. |
| Strength | • Robustness in hardware interfacing and real-world deployment. • Modular design and large ecosystem of tools/libraries. | • Superior performance in high-level tasks and generalization across different task domains. • Leverages state-of-the-art AI advancements. |
| Limitation | • Communication overhead in large-scale robot systems. • Limited AI/ML capabilities. | • Extremely high computational cost. • Dependency on data and compute infrastructure for training and inference. |
| Application | • Autonomous navigation, robotic arm control, sensor fusion, multi-robot systems. | • Task planning using natural language, multi-modal reasoning, human-robot interaction. |
| Principle | Advantages | Disadvantages | |
| Camera | Recognizes surrounding objects using photosensitive sensor | Cost-effectiveness, measurements of texture, color, and contrast | Sensitive to weather conditions, short detection range |
| Radar | Measures distance and speed using electromagnetic wave | Long-distance object detection, weather resistance, and material penetration detection | Difficult to identify the shape of objects, and low resolution |
| LiDAR | Measures distance, shape, and speed using laser | High resolution detection compared to radar | High cost, cannot penetrate objects, shorter detection range compared to radar |
| IMU | Measures motion and orientation using accelerometers and gyroscopes | Compact, lightweight, and capable of high-frequency measurements | Accumulates drift over time, requiring correction from other sensors |
| Microphone | Converts sound waves into electrical signals | Enables voice recognition, sound localization, and interaction with humans | Sensitive to background noise, limited to auditory applications |
| Ultrasonic sensor | Measures distance using high-frequency sound waves | Extremely low cost | Very limited range |
| Sensor type | Sensing frequency | Resolution | Sensitivity | Data volume | Applications by robot type |
| Camera | 30–60 fps | High (e.g., 4K) | High | Very large | Mobile robots: visual SLAM [ 78 , 79 ] Autonomous vehicles: lane detection [ 80 ] , object recognition [ 81 ] Humanoid robots: Human interaction / medical triage / security alert |
| Radar | 20–100 Hz | Medium | Moderate | Moderate | Autonomous vehicles: Obstacle detection in adverse weather [ 82 , 83 ] Industrial robots: Machinery monitoring [ 84 ] |
| LiDAR | 10 Hz | High (mm-level) | High | Large | Autonomous vehicles: navigation and obstacle avoidance [ 85 ] Agriculture robots: Plant detection and mapping [ 86 , 87 ] |
| IMU | 50-1000 Hz | Medium | Low | Low | Drones: Flight stabilization [ 88 ] Humanoid: Balance and motion tracking [ 89 ] Autonomous vehicles: Dead reckoning [ 90 ] |
| Microphone | 16–48 kHz | Medium | Moderate | Moderate | Service robots: Voice interaction [ 91 ] Surveillance robots: Sound localization [ 92 ] |
| Ultrasonic Sensor | 10–100 Hz | Low to medium | Moderate | Low | Mobile robots: Obstacle avoidance Drones: Altitude sensing Warehouse robots: Proximity detection |
| Ref. | Resources | Architecture | Application | AI model | Control strategy | Features in robotics |
| [ 123 ] | Processing & networking | Mobile-cloud | cloud storage, offloading | None | Distributed | Energy efficiency |
| [ 124 ] | Processing & networking | Mobile-edge-cloud | IoT applications | None | Centralized & distributed | Load balancing |
| [ 125 ] | Processing & networking | Mobile-SBS-MBS | Hierarchical edge computing | None | Distributed | Hybrid control |
| [ 126 ] | Storage & networking | Mobile-edge | Contents/service caching | None | Centralized & distributed | AI model caching |
| [ 127 ] | Storage & networking | Mobile-BS | Video streaming | None | Centralized & distributed | Robot-human interaction |
| [ 128 ] | Storage & networking | Mobile-edge-cloud | Cloud gaming | None | Centralized | Low latency |
| Metric | Cloud LLM | Edge LLM | On-Device LLM |
| Processor | A100 GPU | A10 GPU | Octa-core ARM CPU |
| Model | ChatGPT-4o | LLaMA 2 | TinyLLaMA |
| Model size | 100B+ | 13–30B | 1–7B |
| Prefill throughput | 500–1000 tokens/s | 80–250 tokens/s | 10–30 tokens/s |
| Decode throughput | 200–400 tokens/s | 30–100 tokens/s | 3–10 tokens/s |
| Connectivity | Internet | Local | Not required |
| Uplink sensing type | Payload (per update) | Notes |
| Raw image streaming (bit-based) | MB | 8-bit quantized images (LORC-P) |
| Semantic features (proposed) | real values | e.g., features (LORC-SC/LORC-SC-P) |
| JSON field | Meaning (objective/constraint/parameter) |
| pp_config.objective | Planning objective type: makespan (minimize ) or safety_first (tighten safety constraints around predicted humans and conflicts). |
| pp_config.priority_robot | Conflict priority policy: robot_1 / robot_2 / none . When a conflict is detected, the lower-priority robot is constrained (rerouted / delayed) first. |
| pp_config.min_time_gap_at_conflict | Temporal separation constraint (integer time steps) imposed at shared/conflicting cells to reduce close encounters, especially under safety-first operation. |
| ra_config.fairness | Wireless fairness policy: max_min (protect worst-case robot) or proportional (maximize weighted style utility). |
| ra_config.priority_weights | Per-robot weights (e.g., , ) used to reflect task criticality in the chosen fairness policy. |
| Method | Semantic sensing | Predictive link context | Central replanning |
| Stop-and-Go | – | – | – |
| LORC-P | – (raw images) | ✓ | ✓ |
| LORC-SC | ✓ | – (reactive pilots) | ✓ |
| LORC-SC-P | ✓ | ✓ | ✓ |
| Experimental Setup | ||
| CPU | AMD Ryzen 5950X (16C/32T) | |
| GPU | 2 NVIDIA RTX 3090 (24 GB VRAM) | |
| GPU usage | GPU 0: semantic encoder + YOLOv8n, GPU 1: LLaMA 3 8B | |
| Latency Breakdown | ||
| Stage | Role in loop | Latency |
| Object detection (YOLOv8n) | on-robot trigger | ms |
| Method | Scenario 1 (Short) | Scenario 2 (Medium) | Scenario 3 (Long) | Scenario 4 (Long+Obstacles) |
| Stop-and-Go | 72.0 | 151.0 | 209.0 | 209.5 |
| LORC-SC-P | 66.0 | 77.5 | 108.0 | 117.0 |
| LORC-P | 110.0 | 127.0 | 179.5 | 189.5 |
| LORC-SC | 78.5 | 93.5 | 128.5 | 138.0 |
| Baseline | TP gain (%) | Latency reduction (%) |
| Ideal MCS policy ( ) | -14.31 | -39.95 |
| Baseline t–1 | 2.83 | -0.03 |
| Baseline t–3 | 14.14 | 11.62 |
| Baseline t–5 | 26.43 | 20.23 |
| Baseline t–10 | 44.77 | 29.15 |
| Baseline t–20 | 102.68 | 40.89 |
| Mode | Enc. | Comm. | Dec. | Total | Payload | MSE |
| (ms) | (ms) | (ms) | (ms) | (KB) | diff | |
| JPEG (Q=95) | 6.5 | 22.34 20.26 | 1.6 | 30.44 | 80.00 | 0 |
| JPEG (Q=80) | 5.6 | 22.32 19.90 | 1.5 | 29.42 | 33.38 | 0.00017 |
| JPEG (Q=60) | 5.4 | 21.68 12.26 | 1.5 | 28.58 | 22.28 | 0.00025 |
| ViT-small (grid ) | 76.4 | 14.01 7.85 | 3.6 | 94.1 | 5.16 | 0.00225 |
| ViT-small (grid ) | 54.5 | 12.28 6.42 | 2.4 | 69.25 | 3.44 | 0.00279 |
| Method | Sensing policy | Avg. payload (KB) | CTA mean (ms) | CTA 95% (ms) | UTFR (%) | Success ratio (%) |
| JPEG-only (HQ) | Fixed JPEG streaming (Q=95), reliable QoS | 420.0 | 118.75 188.83 | 514.77 | 63.73 | 75 |
| JPEG-only (LQ) | Fixed JPEG streaming (Q=60), best-effort QoS | 120.0 | 108.10 157.82 | 363.87 | 26.47 | 75 |
| ViT-only | Fixed ViT embedding ( ), best-effort QoS | 1.72 | 7.99 6.86 | 17.93 | 25.37 | 75 |
| Orchestrated | LLM-powered switch: JPEG(Q=80) ViT( or ) + QoS adaptation | 15.04 | 19.60 9.69 | 32.62 | 8.47 | 100 |
| Method | Perception stack | Corridor cam | Open-vocab | Item det. success (%) | Bin det. success (%) | Task time (s) | Success ratio (%) |
| Baseline A | On-device closed-set detector + exploration | – | No | 40–50 | 0 | Almost Fail | 0 |
| Baseline B | On-device closed-set retrained for bins/items | – | No | 50–70 | 70–90 | (Seldom Fail) | 40–50 |
| Proposed | Edge MLLM grounding + multi-view (robot + corridor) | ✓ | Yes | 90–95 | 90–100 | 90–100 |
| Demo | Task + environment | Orchestrated knobs (sense/comm/compute) | Measured (or reported) outcomes |
| Demo I | Warehouse navigation in a ray-tracing digital twin with dynamic humans; two robots must reach goals safely under link variability. | Sense: raw RGB-D vs. compact semantic features; Comm: predictive path-gain-aware adaptation; Compute: server-side global replanning parameterized by schema-valid JSON. | Task completion time across scenarios; end-to-end RTT feasibility relative to grid-transition time; qualitative trajectory stability (halt/wait reduction). |
| Demo II | Mobility scenario with fast channel variation and delayed feedback; proactive MCS control under reliability constraint. | Sense: uplink semantic features as link-prediction context; Comm: predictive MCS selection with target BLER; Compute: centralized MLLM infers near-future link proxy under delay. | Throughput/latency/BLER time-series stability and SNR-conditioned performance; aggregate gains under delayed feedback. |
| Demo III | Real FollowMe robot in an indoor corridor over WiFi; maintain smooth tracking/control under interference and range variation. | Sense: JPEG streaming vs. ViT embedding switch; Comm: practical QoS choice (reliable vs. best-effort); Compute: edge tracking/control with closed-loop delay sensitivity. | Codec microbenchmark (payload/latency/MSE); CTA/UTFR and run success. |
| Demo IV | Real mobile manipulation: open-vocabulary trash sorting across room (item) and corridor (bins) using multi-view sensing. | Sense: robot camera + corridor camera; semantic-sensing switch; Comm: multi-view uplink + bbox/goal downlink; Compute: edge MLLM grounding + goal parsing; Act: grasp + SLAM navigation + disposal. | Open-vocabulary detection success (IoU-based); time-to-first item/bin localization; end-to-end task completion time; success ratio. |
| Signal / loop (examples) | Typical rate | Typical payload | What to report (task-facing, measurable) |
| Safety interlock (e-stop, proximity alert, speed limit) | event + 10–100 Hz beacons | 10–200 B | Tail deadline reliability, e.g., delivery within – ms; bounded jitter; verified safe fallback if deadline missed. |
| Coordination state (pose, grasp state, handoff intent) | 30–100 Hz | 0.2–2 KB | Age-of-information (AoI) distribution and sync error (ms); th% AoI within – ms to avoid stale handoff decisions. |
| Semantic perception (tracks, keypoints, embeddings, scene graph updates) | 10–30 Hz | 1–50 KB | End-to-end tail delay (e.g., th% within – ms) and its impact on cycle time / error rate under contention. |
| High-fidelity video / logging / remote QA | 5–30 Hz | 0.1–3 MB | Sustained goodput (Mbps) and graceful degradation (best-effort acceptable) without harming safety/coordination traffic. |
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