Modeling Language For Hybrid Systems Research Articles

Dynamic Reduction of Guarded Constraints for the Hybrid Systems Modeling Language HydLa

Dynamic Reduction of Guarded Constraints for the Hybrid Systems Modeling Language HydLa

Formal verification of ECML hybrid models with spaceex

ContextECML is a modeling language for hybrid systems, proposed by ETRI in Korea. ECML extended the basic formalism, DEV&DESS, with uses in modeling and simulation, whereas algorithmic verification on the ECML models continues to be an on-going research task. ObjectiveThis paper proposes a verification technique to verify ECML models with SpaceEx, a verification platform for hybrid systems. It includes translation rules from ECML into the SpaceEx model. MethodAs SpaceEx reads linear hybrid automata, we developed translation rules from ECML models to linear hybrid automata and implemented an automatic translator ECMLtoSpaceEx. We also developed a rule checker ECML Checker to check whether an ECML model complies with assumptions and restrictions to overcome the semantic gap between the two formal languages. We performed a case study with an extension of the widely used example ‘barrel-filler system’ to demonstrate the effectiveness of our verification technique. ResultsThe verification result shows that our verification technique can translate ECML models into SpaceEx models, and we also perform formal verification on ECML models with SpaceEx. ConclusionsThe proposed technique can verify ECML with support fromSpaceEx. We expect that the proposed translation rules can be used with minor modifications to translate ECML models into different notations, and thus allow for the use of verification tools other than SpaceEx.

A Compositional Modelling and Verification Framework for Stochastic Hybrid Systems

Abstract In this paper, we propose a general compositional approach for modelling and verification of stochastic hybrid systems (SHSs). We extend Hybrid CSP (HCSP), a very expressive process algebra-like formal modeling language for hybrid systems, by introducing probability and stochasticity to model SHSs, which we call stochastic HCSP (SHCSP). Especially, non-deterministic choice is replaced by probabilistic choice, ordinary differential equations are replaced by stochastic differential equations (SDEs), and communication interrupts are generalized by communication interrupts with weights. We extend Hybrid Hoare Logic to specify and reason about SHCSP processes: On the one hand, we introduce the probabilistic formulas for describing probabilistic states, and on the other hand, we propose the notions of local stochastic differential invariants for characterizing SDEs and global loop invariants for repetition. Throughout the paper, we demonstrate our approach by an aircraft running example.

中国高速铁路列控系统的形式化分析与验证

It is essential that the correctness of high-speed train control systems be guaranteed by formal verification because they are safety-critical. However, as these systems become increasingly more complicated, achieving this goal in practice is difficult, and may even be infeasible. On the other hand, it is more convenient to graphically model a complicated system. A graphical model is fairly intuitive, which has resulted in such models being used extensively in industry. Thus, to improve the reliability of a high-speed train control system, constructing a graphical model for the system and then detecting its bugs by simulation should be very effective. In this paper, we first show how to use Simulink/Stateflow to build graphical models for various combined scenarios of Chinese train control systems (CTCS), in which mode conversion and level upgrade take place simultaneously. This modeling approach can be easily adapted to model other scenarios in CTCS by simply modifying the corresponding parameters. Then, we analyze these graphical models via simulations and show that under some circumstances the trains will stop abnormally. Finally, in order to avoid the inherent incompleteness of simulation, we show how to translate these graphical models into formal models given in HCSP-a formal modeling language for hybrid systems that extends CSP-and subsequently formally prove that abnormal stops can happen in many of the cases in one of the combined scenarios. Formal verification of Simulink/Stateflow diagrams complements simulation and improves the reliability of systems being developed.

Modeling and Simulation of Hybrid Systems in MATLAB

Earlier research in the modeling and simulation of hybrid systems led to the development of a general hybrid systems modeling language (HSML) that has been described elsewhere. Effort is underway to implement this concept in software. First, the standard matlab model framework and integration algorithms were extended to support state-event handling in continuous-time components, including approaches for dealing with vector-field conflicts and changing model order and structure. More recently, further extensions have been made to handle embedded discrete-time components.In this paper we describe the algorithmic implementation of the HSML ideas and language constructs for dealing with state events and embedded discrete-time modules in MATLAB. An example will be presented to show the efficacy of these extensions.