Research On The Key Technologies For Safety And Security Controls Of Industrial Control Systems

With the development of the Internet of things and the integrating of informatization and industrialization,industrial control systems(IASs)have been widely used in various safety-critical systems which have direct implications on the national economy and the people's livelihood.And IASs gradually became the brain and nervous centralis of the nation's critical infrastructure and various industrial productions.If there is any problem emerges in IASs,it may lead to severe accidents ranging from the light damage about economic and property loss to the heavy damage about personal and widespread environmental loss.Therefore,safety and security control technologies play a vital role for the efficient and stable operation of IASs.The research work in this dissertation focuses on investigation some key technologies of safety and security control technologies for IASs.Our study includes functional safety guarantee,the architecture of security protection,intrusion detection,intrusion response and the coordinated control and optimization of functional safety and security.The main contributions of this dissertation focus on the following.Transient faults,with a large amount of wide complex types,have become a key factor that influences functional safety of IASs.This dissertation proposed a guarantee approach of functional safety based on transient fault tolerant control after summarizing of the guarantee of functional safety,fault tolerant control and the relations between them.In the proposed approach,the transient fault is detected and recovered at both node layer and system layer by using fault characteristics and system knowledge.Furthermore,the proposed approach is applied to a vehicle brake by wire system as a case.With the large-scale application of ICTs,IAS efficiency is increased and operation maintenance costs are lower.However,the IAS also becomes vulnerable to remote attacks with potential catastrophic consequences.The security protection architecture is researched to slove the security issue in IASs,and a real-time dynamic security protection framework with a "detection-response(including assessment,decision and enforcement)" closed loop structure is designed for the field control layer.To slove the intrusion detection issue in the dynamic security protection,a multi-model based anomaly intrusion detection is proposed.The multiple models of field control system are constructed through synthesizing of the multi-domain knowledge,and then,an anomaly detection algorithm based on multi-angle is designed.Furthermore,an intelligent classifier based on hidden markov model is presented to differentiate attacks from faults and improve the detection accuracy and the detection rate.Simulation experiments show that the method could quickly and efficiently detect attacks in industrial control systems.To slove the intrusion response issue in the dynamic security protection,a real-time control approach of intrusion response in IASs is proposed,which consists of response task generation and integration of scheduling.The non-dominated sorting genetic algorithm II is applied to slove the problem of intrusion response task set generation,and then,a distributed integrated task scheduling and optimization algorithm based on genetic algorithm and directed acyclic graph is designed.Results from numerical simulations show that the proposed method can implement the security policy in time with little effect on the system.Functional safety and security are two sides of the safety and security controls of IASs,and they are closely associated with each other.In this dissertation,the similarities and differences between functional safety and security are analyzed.On the one hand,the procedure of coordinated control and optimization of functional safety and security is proposed for design of new IASs.On the other hand,a comprehensive safety and security control framework including the prevention-based safety and security control and dynamic safety and security control is designed for the existing systems.Finally,a summary of this dissertation is presented,the deficiencies are explained and the future of safety and security control technologies for IASs is prospected.