Research On Evaluation Method Of Business-Based Process Security Protection Capabilitv Of Industrial Control System Based On State Space Model

With the deep integration of human-machine-physical,the security problems of industrial control systems have been exposed a lot.Based on the precise dynamic model of the industrial control system,this paper studies the system business-based process security model and security protection capability evaluation method.This article starts from the following aspects.1)Starting from the concepts of industrial control system construction,industrial control security basic theory,business based process safety theory,etc.,the deficiencies of today's research results are summarized,and the overall research ideas and innovations of this paper are briefly described.2)First,based on the state space model of the industrial control system,the similarities and differences between network attack events,equipment failure events,and noise disturbances were discussed in detail,so as to establish the formalization of the network attack behavior and defense behavior of STUXNET virus false data injection attack;Secondly,based on the critical state variables in the state space model,the security boundary of the system behavior is analyzed,and the minimum time to disaster index for the attack return and the minimum time to resolution index for the defense return are proposed.Finally,the system reliability and attack resistance are established.Fusion-oriented dynamic security model for security business-based processes and security protection capability indicators.3)In order to solve the problem of high complexity and unreliability of the calculation task of minimum time to disaster and minimum time to resolution under multiple constraints in a MISO closed-loop control system containing a single critical state variable,a minimum based on Euler approximation method is proposed.The estimation algorithm of the upper and lower bounds of the minimum time to disaster and the minimum time to resolution strictly proves the correctness of the method.Finally,the simulation and experiments of a non-isothermal CSTR process control system with a PI controller verify the usability and effectiveness of the method.4)In order to solve the problem of ambiguity in the security risk transmission link caused by the serious coupling of multiple critical state variables and input variables in a MIMO closed-loop control system containing multiple critical state variables,a causal relationship between the extracted variables was constructed by studying Based on the differential equation variable sensitivity analysis theory,the criterion of the synergy between the input variables and the critical variables improves the estimation method of the minimum time to disaster upper bound in MIMO systems,and strictly proves the correctness of the method.The simulation experiment of the four-tank water tank liquid level process control system of the reactor verifies the availability and effectiveness of the method.Finally,the full text is summarized,and further research work is prospected.