scholarly journals Counterexample-Guided Abstraction-Refinement for Hybrid Systems Diagnosability Analysis

10.29007/t8n3 ◽  
2018 ◽  
Author(s):  
Hadi Zaatiti ◽  
Lina Ye ◽  
Philippe Dague ◽  
Jean-Pierre Gallois
Keyword(s):  
Hybrid Systems ◽  
Hybrid System ◽  
Timed Automata ◽  
Discrete Event ◽  
Fault Detection And Isolation ◽  
Time Constraints ◽  
Design Stage ◽  
Qualitative Level ◽  
On Line ◽  
Spurious Effect

Verifying behavioral or safety properties of hybrid systems, either at design stage such as state reachability and diagnosability, or on-line such as fault detection and isolation is a challenging task. We are concerned here with abstractions oriented towards hybrid systems diagnosability checking. The verification can be done on the abstraction by classical methods developed for discrete event systems extended with time constraints, which provide a counterexample in case of non-diagnosability. The absence of such a counterexample proves the diagnosability of the original hybrid system. In the presence of a counterexample, the first step is to check if it is not a spurious effect of the abstraction and actually exists for the hybrid system, witnessing thus non-diagnosability. Otherwise, we show how to refine the abstraction, guided by the elimination of the counterexample, and continue the process of looking for another counterexample until either a final result is obtained or we reach an inconclusive verdict. We make use of qualitative modeling and reasoning to compute discrete abstractions. Abstractions as timed automata are particularly studied as they allow one to handle time constraints that can be captured at a qualitative level from the hybrid system.

scholarly journals Efficient nonlinear filtering of a singularly perturbed stochastic hybrid system

2011 ◽  
Vol 14 ◽  
pp. 254-270 ◽  
Author(s):  
Jun H. Park ◽  
Boris Rozovskii ◽  
Richard B. Sowers
Keyword(s):  
State Estimation ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Nonlinear Filtering ◽  
Efficient Estimation ◽  
Singularly Perturbed ◽  
Stochastic Hybrid Systems ◽  
Stochastic Hybrid System ◽  
Estimation Scheme ◽  
On Line

AbstractOur focus in this work is to investigate an efficient state estimation scheme for a singularly perturbed stochastic hybrid system. As stochastic hybrid systems have been used recently in diverse areas, the importance of correct and efficient estimation of such systems cannot be overemphasized. The framework of nonlinear filtering provides a suitable ground for on-line estimation. With the help of intrinsic multiscale properties of a system, we obtain an efficient estimation scheme for a stochastic hybrid system.

scholarly journals PARAMETRIC VERIFICATION AND TEST COVERAGE FOR HYBRID AUTOMATA USING THE INVERSE METHOD

2013 ◽  
Vol 24 (02) ◽  
pp. 233-249 ◽  
Author(s):  
LAURENT FRIBOURG ◽  
ULRICH KÜHNE
Keyword(s):  
Hybrid Systems ◽  
Hybrid System ◽  
Inverse Method ◽  
Timed Automata ◽  
Test Coverage ◽  
Hybrid Automata ◽  
System Verification

Hybrid systems combine continuous and discrete behavior. Hybrid Automata are a powerful formalism for the modeling and verification of such systems. A common problem in hybrid system verification is the good parameters problem, which consists in identifying a set of parameter valuations which guarantee a certain behavior of a system. Recently, a method has been presented for attacking this problem for Timed Automata. In this paper, we show the extension of this methodology for hybrid automata with linear and affine dynamics. The method is demonstrated with a hybrid system benchmark from the literature.

scholarly journals Hybrid System Control Using an On-Line Discrete Event Supervisory Strategy

2006 ◽  
pp. 402-408 ◽  
Author(s):  
James Millan ◽  
Siu O’Young
Keyword(s):  
Hybrid System ◽  
Discrete Event ◽  
System Control ◽  
On Line

On-line Optimal Control of a Class of Discrete Event Systems with Real-Time Constraints

2009 ◽  
Vol 20 (2) ◽  
pp. 187-213 ◽  
Author(s):  
Jianfeng Mao ◽  
Christos G. Cassandras
Keyword(s):  
Optimal Control ◽  
Real Time ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Time Constraints ◽  
Event Systems ◽  
On Line

Sensor Fault Isolation Using Qualitative Quantized Modeling With Application to a 3-DOF Nonlinear Vehicle

2004 ◽  
Author(s):  
S. D’Silva ◽  
P. Pisu ◽  
A. Serrani ◽  
G. Rizzoni
Keyword(s):  
Fault Detection ◽  
Low Cost ◽  
Discrete Event ◽  
Computational Effort ◽  
Fault Isolation ◽  
Fault Detection And Isolation ◽  
Sensor Fault ◽  
Sensor Fault Detection ◽  
On Line ◽  
Nonlinear Vehicle Model

Fault detection and isolation has become one of the most important aspects in vehicle control system design. In this paper, we present a technique for single sensor fault detection and isolation in automotive on-board applications. It combines model-based diagnostics and a qualitative modeling approach. The proposed method is appealing as it shifts the computational effort from on-line to off-line, making the algorithm suitable for low-cost real-time applications. The methodology can be cast in the framework of discrete-event fault diagnosis. A depth one transition relation algorithm for qualitative identification which guarantees completeness is developed and applied to a 3-degree-of-freedom (DOF) nonlinear vehicle model. The paper concludes with preliminary simulation results showing the effectiveness of the proposed scheme.

scholarly journals HYBRID SYSTEM CONTROL USING AN ON-LINE DISCRETE EVENT SUPERVISORY STRATEGY

2006 ◽  
Vol 39 (5) ◽  
pp. 402-408
Author(s):  
James Millan ◽  
Siu O'Young
Keyword(s):  
Hybrid System ◽  
Discrete Event ◽  
System Control ◽  
On Line

The split system approach to managing time in simulations of hybrid systems having continuous and discrete event components

SIMULATION ◽  
2011 ◽  
Vol 88 (3) ◽  
pp. 281-298 ◽  
Author(s):  
James Nutaro ◽  
Phani Teja Kuruganti ◽  
Vladimir Protopopescu ◽  
Mallikarjun Shankar
Keyword(s):  
Hybrid Systems ◽  
Hybrid System ◽  
System Approach ◽  
A Priori ◽  
Discrete Event ◽  
Formal Context ◽  
A Priori Knowledge ◽  
Software Packages ◽  
Split System ◽  
Priori Knowledge

The efficient and accurate management of time in simulations of hybrid models is an outstanding engineering problem. General a priori knowledge about the dynamic behavior of the hybrid system (i.e. essentially continuous, essentially discrete, or ‘truly hybrid’) facilitates this task. Indeed, for essentially discrete and essentially continuous systems, existing software packages can be conveniently used to perform quite sophisticated and satisfactory simulations. The situation is different for ‘truly hybrid’ systems, for which direct application of existing software packages results in a lengthy design process, cumbersome software assemblies, inaccurate results, or some combination of these independent of the designer’s a priori knowledge about the system’s structure and behavior. The main goal of this paper is to provide a methodology whereby simulation designers can use a priori knowledge about the hybrid model’s structure to build a straightforward, efficient, and accurate simulator with existing software packages. The proposed methodology is based on a formal decomposition and re-articulation of the hybrid system; this is the main theoretical result of the paper. To set the result in the right perspective, we briefly review the essentially continuous and essentially discrete approaches, which are illustrated with typical examples. Then we present our new, split system approach, first in a general formal context, then in three more specific guises that reflect the viewpoints of three main communities of hybrid system researchers and practitioners. For each of these variants we indicate an implementation path. Our approach is illustrated with an archetypal problem of power grid control.

Autonomy and Responsibility in Hybrid Systems

2017 ◽  
Author(s):  
Wulf Loh ◽  
Janina Loh
Keyword(s):  
Hybrid Systems ◽  
Hybrid System ◽  
Moral Dilemma ◽  
Autonomous Driving ◽  
Shared Responsibility ◽  
Driving System ◽  
Autonomous Cars ◽  
Self Driving Cars ◽  
Trolley Cases ◽  
Autonomous Driving System

In this chapter, we give a brief overview of the traditional notion of responsibility and introduce a concept of distributed responsibility within a responsibility network of engineers, driver, and autonomous driving system. In order to evaluate this concept, we explore the notion of man–machine hybrid systems with regard to self-driving cars and conclude that the unit comprising the car and the operator/driver consists of such a hybrid system that can assume a shared responsibility different from the responsibility of other actors in the responsibility network. Discussing certain moral dilemma situations that are structured much like trolley cases, we deduce that as long as there is something like a driver in autonomous cars as part of the hybrid system, she will have to bear the responsibility for making the morally relevant decisions that are not covered by traffic rules.

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