An End-to-End Tool for Developing CPSs from Design to Implementation

For a Cyber-Physical System (CPS), the real-time execution must be guaranteed at the design time for the safe and reliable interaction between a Cyber and a Physical System. Thus, simulation method is widely used to verify and validate the behavior of a CPS, in the development process. Commercial tools of today, however, only mimic the functional behavior of the system, not the temporal behavior. Moreover, when the simulation target system is changed, developers have to reconfigure all settings to simulate properly. To overcome this limitation, we introduce our End-to-End Development Tool that can support the functional and temporal co-validation and smooth migration for the change of the simulation target system.OAIID:RECH_ACHV_DSTSH_NO:A201617646RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A077084CITE_RATE:FILENAME:V2CPS_final.pdfDEPT_NM:컴퓨터공학부EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/8cf7890c-46ec-4551-9c3e-2715774d7f34/linkCONFIRM:

사이버-물리 시스템을 위한 기능적/시간적 정확성 보장 시뮬레이션 기법

학위논문 (박사)-- 서울대학교 대학원 공과대학 전기·컴퓨터공학부, 2017. 8. 이창건.When developing a Cyber-Physical System (CPS), simulators are commonly used to predict the final performance of the system at the design phase. However, current simulation tools do not consider timing behaviors of the cyber-system such as varying execution times and task preemptions. Thus, their control performance predictions are far different from the real performance, and this leads to enormous time and cost for a system development, because multiple re-design and re-implementation phases are required, until an acceptable system configuration is determined. Motivated by this limitation, this dissertation proposes functionally and temporally correct simulation for the cyber-side of a CPS. The key idea of the proposed approach is to keep the data and time correctness only at the physical interaction points to maximally enjoy the freedom of scheduling simulated jobs. For this, we transform the simulation problem to a real-time job scheduling problem with precedence constraints necessary for the functional and temporal correctness. Then, we propose an efficient scheduling algorithm for the functionally and temporally correct real-time simulation. The proposed approach significantly improves the real-time simulation capacity of the state-of-the-art simulation methods while keeping the functional and temporal correctness. Our evaluation through both synthetic workload and actual implementation confirms both high accuracy and high efficiency of our approach compared with other state-of-the-art methods.1 Introduction 1 1.1 Motivation and Objective 1 1.2 Approach 3 1.3 Contributions 8 1.4 Organization 8 2 Related Work 10 2.1 Design and Verification of Cyber-Physical Systems 10 2.2 Verification Approaches 12 2.2.1 Model-Based Simulations 12 2.2.2 Cycle-Accurate Simulations and Host-Compiled Simulations 14 2.2.3 Real-Time Execution Platforms 15 2.2.4 Distributed Simulations 16 2.3 Job Scheduling Approaches 17 3 System Model and Problem Description 22 3.1 Description on the real cyber-system 23 3.2 Description on the simulated cyber-system 27 3.3 Formal definition of the simulation problem 28 4 Real-Time Simulation for Deterministic Cyber-Systems 31 4.1 Introduction 31 4.2 Construction of Offline Guider 31 4.3 Online Progressive Scheduling of Simulated Jobs 34 4.4 Evaluation 38 5 Real-Time Simulation for Non-Deterministic Cyber-Systems 45 5.1 Introduction 45 5.2 Overview of Approach 45 5.3 Construction of Offline Guider 50 5.4 Online Progressive Scheduling of Simulated Jobs 63 5.5 Evaluation 74 5.5.1 Evaluation Using Synthesized Cyber-Systems 78 5.5.2 Implementation 86 6 Practical Discussions 95 6.1 Data Exchange Delay 95 6.2 Simulation Overhead 97 6.2.1Offline Overhead 97 6.2.2 Online Overhead 100 6.3 Other Useful Features 100 7 Extension for Multicore Simulation PC 102 8 Conclusion 108 8.1 Summary 108 8.2 Future Work 108 References 110Docto