Deep Fuzzy C-Means Clustering in a Federated Heterogeneous Scenario

In federated deep Fuzzy C-Means (FCM) clustering, conventional federated averaging (FedAvg) struggles with non-independent and identically distributed (non-IID) data and dynamic device participation, leading to model drift and performance degradation during global aggregation. To address this challenge, we propose FedFCD, a federated deep FCM clustering method featuring a novel aggregation mechanism. FedFCD equips each client with a hybrid architecture comprising a contrastive autoencoder (CtAE) and an FCM network (FCMNet), which collaboratively learn stable low-dimensional embeddings and refine soft clustering assignments iteratively. At the server side, we design a two-phase aggregation strategy integrating Bayesian ensemble learning and knowledge distillation (KD). First, the Bayesian aggregation mechanism probabilistically fuses heterogeneous local models' inferences into a consensus assignment by treating each client's model as a candidate hypothesis, thereby constructing a posterior distribution over the global model space through iterative evidence accumulation. Subsequently, dual-source distillation harmonizes pseudo-labels derived from the Bayesian consensus with ground-truth labels from limited shared data, enabling the global model to align its predictions with both semantic anchors and aggregated soft assignments while preserving privacy through distillation loss. Comparative experiments on benchmark datasets demonstrate that FedFCD outperforms baseline methods in clustering accuracy and exhibits enhanced stability under varying conditions, including data heterogeneity, device numbers, and device dropout.