Topic: Safety Enhancement for Complex Engineering Systems

Complex engineering systems are becoming increasingly capable and large in scale, raising the bar for safety assurance and making safety-enhancement technologies more critical than ever. Broadly, such technologies can be understood as operating across three interrelated levels: physical safety, information security, and governance compliance. At the foundational level, physical safety requires that, under specified operating conditions and foreseeable failure scenarios, system behavior remains within an acceptable level of risk, emphasizing accident prevention and controllable degradation. Building on this foundation, the information security level focuses on detecting and countering communication attacks, sensor spoofing, and malicious command injection, while ensuring software/model integrity and protecting privacy. At the highest level, governance compliance prioritizes human safety, mandates transparent risk-handling policies, enables post-incident reconstruction of decision chains with clear accountability, and ensures compliance with relevant data protection and cybersecurity regulations.

As physical safety underpins all three layers, this Special Issue aims to provide a forum for researchers and practitioners to share recent advances in safety enhancement for complex engineering systems, including methods for safety modeling, analysis, monitoring, and control under uncertainty and foreseeable failures. With complex systems continuing to grow in capability and scale, safety assurance has become a rapidly expanding research area, driven by high-impact applications across transportation, energy, manufacturing, robotics, aerospace, and other safety-critical domains. This Special Issue seeks original research contributions that advance both the theory and practice of safety enhancement—such as risk assessment, fault diagnosis, fault-tolerant and safe control, runtime monitoring and assurance, and verification and validation—with clear relevance to real-world complex engineering systems. High-quality original papers aligned with the above scope are especially welcome.

Topics include, but are not limited to:

● Safe state estimation and uncertainty quantification;

● Fault diagnosis, prognosis, and health monitoring (Fault Detection and Isolation / Prognostics and Health Management, FDI/PHM);

● Fault-tolerant control and safe degradation (graceful fallback);

● Risk assessment, hazard analysis, and safety case development;

● Runtime monitoring, anomaly detection, and safety supervision;

● Formal verification, reachability analysis, and runtime assurance;

● Safe learning-based control (Reinforcement Learning / Imitation Learning,RL/IL) with constraints and performance guarantees;

● Human-machine interaction safety and shared-control strategies;

● Safety-oriented system architectures (redundancy, diversity, fail-safe design) for deployment;

● Benchmarking, simulation-to-reality validation, and safety testing methodologies for complex systems.

Safety enhancement, complex engineering systems, fault diagnosis, risk assessment, human-machine interaction