Study On Fault Tolerant Control Of Cyber-Physical Systems With Attack

Cyber-Physical Systems(CPS)is an intelligent information system with high performance networking.CPS enhances the system's capabilities in information processing,real-time communication,precision control and autonomous coordination of components and other aspects of capacity,through a series of high integration and interaction of computing units and physical objects in a network environment,CPS is a multi-dimensional space-time heterogeneous hybrid autonomous system with real-time,safe,reliable,high performance and so on.Due to its own distributed architecture and its complexity,CPS is vulnerable to cyber attacks.Attacks will cause incalculable losses an.So we must keep the security before the CPS is utilized.This thesis focuses on the CPS security issues,take UAV formation system and wireless sensor network system two typical CPS as example,presents a fault-tolerant algorithm to make the system work regularly under the attacks.First of all,we consider DOS attacks and false data injection attacks respectively.Design PRR and coding matrix method to detect attack.For intelligent network attacks,often can avoid detection system,so that the attacks can not be found in time by the detection system.The two detection methods were designed to detect network attacks effectively.For the formation of UAV,observer-based controllers with tunable parameters are used to control the system so that it can be coordinated.Assuming that the system is designed to be attacked by DOS,a PRR-based detection method is designed as a fault-tolerant strategy that keeps the system coordinate.For wireless sensor network system,considering its coverage characteristics,a self-adjusting algorithm is designed to enable the system to cover the target area with the largest area.Combined with the PRR detection algorithm,a fault-tolerant strategy is designed to ensure the system still cover the largest area of the target area when attacked.In this paper,we simulate the two systems in different situations and verify that the designed fault-tolerant algorithm can achieve the expected goal.