Developing an Enhanced IHBO Algorithm with Chaotic Binary Hashing to Optimize BiGRU for Industry 4.0 IIoT Anomaly Detection

Abstract

The rapid expansion of the Industrial Internet of Things (IIoT) in Industry 4.0 has increased the need for reliable anomaly detection to protect industrial services and critical operations. Deep learning–based IDS solutions can achieve strong performance, yet practical deployment may be affected by tuning effort and suboptimal search behavior when optimization is trapped in local optima, particularly when feature selection and model optimization are handled as separate stages. This paper develops an enhanced Improved Honey Badger Optimization (IHBO) algorithm and integrates it with a Bidirectional Gated Recurrent Unit (BiGRU) model for IIoT anomaly detection. To strengthen exploration and maintain population diversity during optimization, the proposed IHBO incorporates a logistic chaotic map as a controlled diversification mechanism. In addition, chaotic binary hashing is used to map continuous candidate representations into discrete binary decisions, enabling effective wrapper-based feature selection within the same optimization framework. The main novelty lies in performing integrated feature selection and BiGRU optimization within a single framework rather than treating these steps independently. Experiments on two benchmark datasets—an industrial IIoT dataset and UNSW-NB15—show that the proposed BiGRU–IHBO approach achieves 94.70% accuracy on the IIoT dataset and 99.29% accuracy on UNSW-NB15, with consistent improvements in precision, recall, and F1-score compared with baseline models reported in the same experimental setting.