AI-based worker guidance in assembly and disassembly operations using
multimodal ego/exo-centric data capture and structured task knowledge

Vivek Chavana,b, Jörg Krügera,b*
a Fraunhofer IPK, Germany     b Technical University of Berlin, Germany
CIRP Annals 2026

IndEgo Assistant learns structured industrial procedures from expert demonstrations and reuses that knowledge for context-aware worker guidance. Synchronized egocentric and exocentric video captures complementary hand-object and workspace-level evidence, while expert narration provides procedural intent. The system converts these signals into step-aligned video representations, validated precedence graphs, and instructions for online action recognition and valid next-step guidance.

System Pipeline

IndEgo Assistant consists of two connected phases. During offline procedure learning, multimodal expert demonstrations are transformed into validated task knowledge and trainable video representations. During online worker guidance, the resulting task model observes the worker, tracks execution history, maps the current state onto the validated procedure graph, and recommends the next valid action.

Offline learning · A–G

Learning Procedures from Expert Demonstrations

The offline pipeline captures how an expert performs and explains an industrial procedure. Speech, video, gaze, and complementary camera perspectives are temporally aligned to produce step-level training examples and structured procedural knowledge.

Offline procedure-learning pipeline from expert demonstrations

Offline procedure learning. Raw expert demonstrations are converted into a reviewed procedure graph, step-aligned video–label pairs, and a multimodal task model.

A

Expert Demonstration Capture

An expert performs the assembly or disassembly procedure while synchronized egocentric video, exocentric video, audio narration, and optional eye gaze are recorded. Egocentric video captures the worker's interaction perspective, while exocentric cameras provide complementary workspace and process context.

B

Speech Transcription

WhisperX converts the expert's spoken narration into a temporally aligned transcript. Word- and segment-level timestamps connect procedural descriptions to the corresponding moments in the recordings.

C

Video Segmentation and Synchronization

The recordings are divided into candidate procedural segments using the transcript-derived temporal boundaries. Ego video, exo video, narration, and gaze samples are synchronized so that every segment refers to the same execution interval.

D

Procedure and Task-Graph Extraction

A reasoning language model converts the structured transcript into step labels, procedural instructions, and an initial precedence graph. The graph represents valid ordering constraints, including sequential, parallel, and alternative execution paths.

E

Expert Review

A human expert reviews the automatically generated steps, instructions, temporal boundaries, and graph edges. This validation stage prevents uncertain language-model outputs from becoming authoritative process constraints.

F

Video Representation and Task Adaptation

Step-aligned clips are encoded using a frozen V-JEPA 2 video backbone. With one demonstration, the system stores representations in a retrieval memory bank. With multiple demonstrations, a lightweight task-specific classifier can be trained over the frozen representations.

G

Multimodal Task Model

The validated procedure graph, procedural instructions, video representations, view configuration, and recognition component are packaged into a reusable task model for online assistance.

Egocentric, Exocentric, and Gaze-Aware Understanding

The implementation supports three evaluation modes: ego only, exo only, and ego + exo. Egocentric video provides detailed hand–object interaction evidence from the worker's perspective. Exocentric video provides a wider view of the workspace, object arrangement, body motion, and events that may fall outside the egocentric field of view. In the combined configuration, both perspectives are fused into a fixed multimodal representation.

Eye gaze is available only for the egocentric stream. It is used to construct a gaze-centred or foveal visual representation that complements the full egocentric frame. In exo-only experiments, the gaze feature and its availability mask are explicitly disabled.

Online guidance · H–K

Context-Aware Worker Assistance

During deployment, the system observes the worker's current activity and relates it to both the execution history and the validated procedure graph. Guidance is therefore conditioned not only on visual similarity, but also on which steps are currently permitted by the task structure.

Online context-aware worker-guidance pipeline

Online worker guidance. Live observations are mapped to the learned procedure, combined with execution history, and used to identify the next valid action.

H

Live Worker Observation

The worker's ongoing activity is captured as a stream of short video clips. Depending on the deployment setup, the system can use egocentric observations, exocentric observations, or both, with optional gaze available for the egocentric view.

I

Action Recognition and History Update

The multimodal task model compares the current observation with its learned step representations and predicts or retrieves the most likely procedural step. Confirmed steps are added to the execution history, creating a persistent representation of progress through the task.

J

Procedure Mapping and Planning

The recognized action and execution history are mapped onto the reviewed procedure graph. The planner identifies which successor steps have satisfied prerequisites and are therefore valid at the current point in the procedure.

K

Next-Step Guidance

The system presents one or more valid next actions together with the corresponding procedural instructions. The language model may adapt the wording of the guidance, but it cannot override the constraints encoded in the expert-validated procedure graph.

Models and Their Roles

Component Role in the pipeline
WhisperX Transcribes expert narration and associates the text with temporal boundaries in the demonstration.
Llama 3.1 Extracts procedural steps, instructions, and candidate precedence relations, and can phrase online guidance.
V-JEPA 2 Produces video representations for ego-global, ego-gaze-foveal, and exo-global observations.
Memory bank or linear probe Recognizes task steps using retrieval when data is scarce or lightweight supervised adaptation when multiple demonstrations are available.
Validated procedure graph Constrains planning to steps whose procedural prerequisites have been satisfied.

Overview

Assembly and disassembly processes rely on expert knowledge that is difficult to document, reuse, and transfer. This paper presents a data-centric approach for extracting structured task knowledge from expert demonstrations using egocentric and exocentric recordings. Temporal and multimodal information from video and narration is jointly encoded to derive structured task representations that enable procedural documentation and context-aware worker guidance. The approach is evaluated on a real-world disassembly case study, demonstrating that video-based representations capture procedural structure and execution context beyond static image-based methods. The results highlight the potential of egocentric video understanding for repair, training, and circular manufacturing applications.

Key Contributions

Citation


@article{chavan2026cirpannals,
  title={AI-based worker guidance in assembly and disassembly operations using multimodal ego/exo-centric data capture and structured task knowledge},
  author={Chavan, Vivek and Krüger, Jörg},
  journal={CIRP Annals},
  year={2026}
}