Current Digital Twin (DT) technology lacks the cognitive capabilities needed for true autonomy and intelligent adaptation. This paper introduces CogTwin, a hybrid cognitive architecture framework for developing Cognitive Digital Twins (CDTs). CogTwin integrates a 50ms cognitive cycle inspired by human cognition, dual knowledge graphs (static Domain Knowledge Repository (DKR) and dynamic Internal Knowledge Graph (DIKG)), a hybrid attention mechanism, and self-healing capabilities. Combining symbolic, sub-symbolic, and neuro-symbolic AI, CogTwin enables real-time learning and decision-making. Simulated smart city scenarios, including traffic incident management and power outage response, demonstrate CogTwin’s potential. Preliminary performance evaluations of the pseudocode suggest feasibility of the target 50ms cycle. The architecture also incorporates explainable AI (XAI) for transparency and human-CogTwin collaboration. CogTwin contributes towards a unified theory of cognition for DTs, laying the groundwork for more sophisticated and autonomous CDTs.

A Smart City is one that makes better use of city data to make our communities better places to live. Typically, this has 3 components: sensing (data collection), analysis and actuation. Privacy, particularly as it relates to citizen's data, is a cross-cutting theme. A Digital Twin (DT) is a virtual replica of a real-world physical entity. Cognitive Digital Twins (CDT) are DTs enhanced with cognitive AI capabilities. Both DTs and CDTs have seen adoption in the manufacturing and industrial sectors however cities are slow to adopt these because of privacy concerns. This work attempts to address these concerns by proposing a Privacy Preserving Federated Learning (PPFL) based Cognitive Digital Twin framework for Smart Cities.