CurFed-CHARM: Federated Event-Based Human Action Recognition

A curriculum sequential federated-learning framework for privacy-preserving action recognition across heterogeneous and non-IID event-camera clients.

Computer Vision and Image Understanding · Volume 265 · Article 104696 · 2026

Muhammad Hamza Zafar, Syed Kumayl Raza Moosavi, and Filippo Sanfilippo

Project overview

CurFed-CHARM addresses a practical deployment problem: event-camera data may be distributed across multiple devices and environments, while privacy or bandwidth constraints prevent raw data centralisation. The framework begins with a client containing all action classes and progressively incorporates additional clients after performance thresholds are reached.

Core contributions

  • Curriculum sequential federated learning for progressively integrating heterogeneous clients.
  • A channel-hierarchical action-recognition model with attention-enhanced 3D convolutional processing.
  • Privacy-preserving training without sharing raw event-camera recordings.
  • Specialized metrics for client convergence, knowledge transfer, catastrophic forgetting, and communication efficiency.

Reported evidence

94.87%average accuracy across clients on E-FedAct
27.3%reported reduction in communication cost
60%improvement in knowledge-transfer efficiency from global temporal attention

The reported average accuracy exceeds FedAvg at 92.99%, FedProx at 92.42%, and FedCurv at 92.09%. The study also analyses convergence behavior, client progression, forgetting, and communication overhead.

Datasets and evaluation

  • E-FedAct, structured to represent heterogeneous client-wise action data.
  • Non-IID scenarios with different action-class distributions across clients.
  • Evaluation across standard classification measures and federated-learning-specific metrics.

Relevance to human-in-the-loop robotics

Distributed human-aware robots and smart environments cannot always centralize sensitive recordings. CurFed-CHARM provides a route to collaborative model learning across devices while keeping raw event data local and controlling communication demands.