Aspect-Oriented Fault-Tolerant Scheduling Model For Real-Time System In Cyber Physical Systems

With the development of computing technology, network technology and control technology, a kind of the newest complex system called Cyber-physical Systems arises at the historic moment. Cyber-physical Systems is the next-generation intelligent system which has integrated computing, communication and control by 3C technology and 3i technology. The high reliability requirements of Cyber-physical Systems affecting its security and control have become the key factor, and improving real-time system reliability in CPS is of great significance. The fault-tolerant scheduling is an important technology for guaranteeing the reliability of real-time system. Nowadays, it has become research hotspot in real-time system. Therefore, researching and designing a fault-tolerant scheduling model and algorithm, which is efficient, simple and can adapt to the Cyber Physical real-time systems, is the most important question to solve in Cyber-physical Systems. This article is in this background to research fault-tolerant scheduling model and algorithm in Cyber-physical Systems.Firstly, this paper introduced the structure of Cyber-physical Systems, the relationship between Cyber-physical Systems and the Internet of Things, and the new characteristics of Cyber-physical Systems. Then it introduced aspect-oriented programming technology and UML expansion mechanism, using UML expanding framework to realize UML extension with aspect-oriented modeling technology and crosscutting point separation technology. And these provide visualizations graphics model for the fault-tolerant analysis of real-time system in Cyber-physical Systems. Based on these, this paper made a deep research on fault-tolerant scheduling model in Cyber-physical Systems, and the main work is as follows:1. This paper introduced UML in aspect-oriented expansion mechanism and realized aspect-oriented visualized modeling. Using UMLTM to build a fault tolerant view for fault-tolerant aspect and time aspect of real-time system and combining the visualization of real-time system in Cyber Physical environment, aspect-oriented thoughts will be applied to analysis the distributed real-time system fault tolerance scheduling model and algorithm in Cyber Physical network environment through UMLTM framework.2. This paper raised the concept of the distributed real-time system in Cyber-physical Systems, analyzed its basic features, offered a basic task model and proved the schedulability of task. What's more, it provided an evaluation system to analyze the performance of task scheduling algorithm for CPS heterogeneous distributed real-time system.3. This paper put forward two fault-tolerant scheduling algorithms, CPS real-time tasks dynamic load balancing algorithm (CPS_DLBA) and aspect-oriented CPS fault-tolerant real-time algorithm (AO_CPS_RTFT), which are suitable for real-time system in Cyber-physical Systems. Through simulation experiment, this paper comprised them on the algorithm balanced and task load rate and concluded that AO_CPS_RTFT is more superior CPS DLBFT.4. This paper illustrated the basic concept of Cyber-physical Systems and the usage of aspect-oriented fault-tolerant scheduling model in CPS heterogeneous distributed real-time system by the example of City Subway System. The example fully embodies the advantages of aspect-oriented technology and UML expansion mechanism visualized modeling in Cyber-physical Systems.