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Cyber-physical systems (CPS) tightly integrate cyber and physical components and transcend discrete and continuous domains. It is greatly desired that the synergy between cyber and physical components of CPS is explored even before the complete system is put together. Virtualization has potential to play a significant role in exploring such synergy. In this paper, we propose a CPS virtualization approach based on the integration of virtual machine and physical component emulator. It enables real software, virtual hardware, and virtual physical components to execute in a holistic virtual execution environment. We have implemented this approach using QEMU as the virtual machine and Matlab/Simulink as the physical component emulator, respectively. To achieve high-fidelity between the real system and its virtualization, we have developed a strategy for synchronizing the virtual machine and the physical component emulator. To evaluate our approach, we have successfully applied it to real-world control systems. Experiments results have shown that our approach achieves high-fidelity in capturing dynamic behaviors of the entire system. This approach is promising in enabling early development of cyber components of CPS and early exploration of the synergy of cyber and physical components.

Hybrid systems such as Cyber Physical System (CPS) are becoming increasingly popular, mainly due to the involvement of information technology in different aspects of life. For analysis and verification of hybrid system models, simulation is used extensively. As parts of a common hybrid system may belong to different domains of study, it is sometimes beneficial to use specialized simulation packages (SPs) for each domain. In this case, parts of a system are simulated in different SPs. The idea may seem simple, but coupling more than one simulation component presents challenges related to numerical stability. The presented article suggests an implicit solver coupling technique enhanced to facilitate simulation of hybrid models using multiple simulation components. The technique is developed using two of the most popular simulation interoperability standards, namely, the High Level Architecture and the Functional Mock-up Interface. By using these standards, the developed algorithm will be useful for a large number of practitioners and researchers. The developed algorithm is described using a generic distributed computation model, which makes it reproducible even without using the standards. For the verification of results, the algorithm is tested on two case studies. The results are compared to a monolithic simulator and the proximity of results initiates the validity of the developed algorithm.

In order to get the hydraulic excavator mechanical-hydraulic coupling characteristics, the models of hydraulic and mechanical system are built in AMESim and Virtual Lab Motion. By the joint simulation interface, mechanical and hydraulic models can exchange data in time. The characteristics of excavator work device are analyzed in the aspects of cylinder movement situations and pressure changes as shown in Fig. 4 and Fig. 5. The max pressure exists in the arm cylinder and the value is 29.2MPa, which is smaller than the relief pressure. The excavator can work normally under the design load.

Three-dimensional modeling software and dynamics simulation software were used for fatigue design of the connecting rod. Dynamics simulation model of crankshaft system was established and the load of connecting rod was obtained. Non-linear contact analytical method of static strength was adopted to accomplish the stress distribution of the connecting rod. On the basis of the static strength analysis, fatigue life and fatigue safety factor of the connecting rod were get by fatigue strength analysis. Compared with experiment and engineering calculations, co-simulation method of multi-software is more economic and accurate. Furthermore, optimal design of the connecting rod would be benefit from the calculation results.