Bayesian hybrid automata: Reconciling formal methods with metrology

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Paul Kröger ◽  
Martin Fränzle
Keyword(s):  
System Dynamics ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Formal Model ◽  
Continuous Control ◽  
Hybrid Automata ◽  
Physical Processes ◽  
Natural Domain ◽  
State Tracking ◽  
Smart Technologies

Abstract Hybrid system dynamics arises when discrete actions meet continuous behaviour due to physical processes and continuous control. A natural domain of such systems are emerging smart technologies which add elements of intelligence, co-operation, and adaptivity to physical entities. Various flavours of hybrid automata have been suggested as a means to formally analyse dynamics of such systems. In this article, we present our current work on a revised formal model that is able to represent state tracking and estimation in hybrid systems and thereby enhancing precision of verification verdicts.

scholarly journals Approximate Equivalence of the Hybrid Automata with Taylor Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Anping He ◽  
Jinzhao Wu ◽  
Shihan Yang ◽  
Hongyan Tan
Keyword(s):  
Hybrid System ◽  
Equivalence Relation ◽  
Formal Model ◽  
Reachability Analysis ◽  
Hybrid Automata ◽  
Hybrid Automaton ◽  
Taylor Approximation ◽  
Computational Processes ◽  
Simulation Relation

Hybrid automaton is a formal model for precisely describing a hybrid system in which the computational processes interact with the physical ones. The reachability analysis of the polynomial hybrid automaton is decidable, which makes theTaylorapproximation of a hybrid automaton applicable and valuable. In this paper, we studied the simulation relation among the hybrid automaton and its Taylor approximation, as well as the approximate equivalence relation. We also proved that the Taylor approximation simulates its original hybrid automaton, and similar hybrid automata could be compared quantitatively, for example, the approximate equivalence we proposed in the paper.

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.

Linear and nonlinear dynamics of hybrid systems

2020 ◽  
pp. 095440622095769
Author(s):  
Katica R (Stevanović) Hedrih
Keyword(s):  
Nonlinear Dynamics ◽  
System Dynamics ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Deformable Body ◽  
Transfer Energy ◽  
Deformable Bodies ◽  
Inertia Properties ◽  
Linear And Nonlinear ◽  
Axially Moving

Discrete continuum method for investigation of linear and nonlinear dynamics of hybrid systems containing coupled multi deformable bodies is presented. By use coupled rods, beams, strings, plates and membranes by discrete continuum mass less layers as well as layers with translator and rotator inertia properties into series of hybrid system dynamics are investigated and phenomenological mappings in dynamics of these different real systems are identified. Expressions of generalized forces of subsystem interactions in hybrid system are presented by component mechanical energies and functions of energy dissipations. A model of dynamical dislocations with inertia properties in plate is presented. Transfer energy between subsystems is investigated. Constitutive relation of standard elements of discrete continuum coupling layers with translator and rolling inertia properties, nonlinear elastic and fractional order properties are presented. Interaction between two coupled linear and nonlinear system, each with one degree of freedom as well as dynamics of discrete no homogeneous chain are considered in the light of mathematical analogy for obtaining eigen time functions of solutions of component deformable body displacements in hybrid system dynamics. For pointing out the major contributions outlined in the manuscript it is necessary to add: The manuscript contains reviews on results obtained of a few scientific problems of nonlinear dynamics, namely, for stochastic stability of vibration modes of a parametrically excited sandwich beam, transversal vibrations of axially moving double belt system, multi deformable bodies coupled by standard light fractional type discrete continuum layers. New model of dynamical dislocation in continuum is proposed and analyzed Series of the original results of author’s doctorates supervised is listed.

scholarly journals A Review of Hybrid Automata Models

2021 ◽  
Author(s):  
Mohammad Reza Besharati ◽  
Mohammad Izadi
Keyword(s):  
Hybrid Systems ◽  
Formal Model ◽  
Hybrid Automata

In this paper, Hybrid Automata, which is a formal model for hybrid systems, has been introduced. A summary of its theory is presented and some of its special and important classes are listed and some properties that can be studied and checked for it are mentioned. Finally, the purposes of use, the most widely used areas, and the tools that provide H.A. Support are addressed.

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.

Fuel-Cell Hybrid Systems to Generate Shipboard Electrical Power

2009 ◽  
Author(s):  
W. J. Sembler ◽  
S. Kumar
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Air Quality ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Cell Hybrid ◽  
Electrical Power ◽  
History Of ◽  
Marine Applications ◽  
Fuel Cell Hybrid

The reduction of shipboard airborne emissions has been receiving increased attention due to the desire to improve air quality and reduce the generation of greenhouse gases. The use of a fuel cell could represent an environmentally friendly way for a ship to generate in-port electrical power that would eliminate the need to operate diesel-driven generators or use shore power. This paper includes a brief description of the various types of fuel cells in use today, together with a review of the history of fuel cells in marine applications. In addition, the results of a feasibility study conducted to evaluate the use of a fuel-cell hybrid system to produce shipboard electrical power are presented.

scholarly journals Optimal Sizing of a Pv-Wind Hybrid System Using Measured and Generated Database

2021 ◽  
Vol 03 (01) ◽  
pp. 34-44
Author(s):  
Abdellah Benallal ◽  
◽  
Nawel Cheggaga ◽  
Keyword(s):  
Renewable Energy ◽  
Wind Speed ◽  
Wind Turbine ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Measured Data ◽  
Electrical Load ◽  
Wind Potential ◽  
Simulation Results ◽  
The Cost

Renewable energy hybrid systems give a good solution in isolated sites, in the Algerian desert; wind and solar potentials are considerably perfect for a combination in a renewable energy hybrid system to satisfy local village electrical load and minimize the storage requirements, which leads to reduce the cost of the installation. For a good sizing, it is essential to know accurately the solar potential of the installation area also wind potential at the same height where wind electric generators will be placed. In this work, we optimize a completely autonomous PV-wind hybrid system and show the techno-economical effects of the height of the wind turbine on the sizing of the hybrid system. We also compare the simulation results obtained from using wind speed measured data at 10 meters and 40 meters of height with the ones obtained from using wind speed extrapolation on HOMER software.

Condition-based opportunistic maintenance policy for a series–parallel hybrid system with economic dependence

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aiping Jiang ◽  
Zhenni Huang ◽  
Jiahui Xu ◽  
Xuemin Xu
Keyword(s):  
Hybrid Systems ◽  
Hybrid System ◽  
Maintenance Policy ◽  
Economic Dependence ◽  
Opportunistic Maintenance ◽  
Content Type ◽  
Cost Rate ◽  
Parallel Hybrid ◽  
In Series ◽  
Redundant Structure

PurposeThe purpose of this paper is to propose a condition-based opportunistic maintenance policy considering economic dependence for a series–parallel hybrid system with a K-out-of-N redundant structure, where a single component in series is denoted as subsystem1, and K-out-of-N redundant structure is denoted as subsystem2.Design/methodology/approachBased on the theory of Residual Useful Life (RUL), inspection points are determined, and then different maintenance actions are adopted in the purpose of minimizing the cost rate. Both perfect and imperfect maintenance actions are carried out for subsystem1. More significantly, regarding economic dependence, condition-based opportunistic maintenance is designed for the series–parallel hybrid system: preemptive maintenance for subsystem1, and both preemptive and postponed maintenance for subsystem2.FindingsThe sensitivity analysis indicates that the proposed policy outperforms two classical maintenance policies, incurring the lowest total cost rate under the context of both heterogeneous and quasi-homogeneous K-out-of-N subsystems.Practical implicationsThis model can be applied in series–parallel systems with redundant structures that are widely used in power transmission systems in electric power plants, manufacturing systems in textile factories and sewerage systems. Considering inconvenience and high cost incurred in the inspection of hybrid systems, this model helps production managers better maintain these systems.Originality/valueIn maintenance literature, much attention has been received in repairing strategies on hybrid systems with economic dependence considering preemptive maintenance. Limited work has considered postponed maintenance. However, this paper uses both condition-based preemptive and postponed maintenance on the issue of economic dependence bringing opportunities for grouping maintenance activities for a series–parallel hybrid system.

scholarly journals End-to-End Safe Reinforcement Learning through Barrier Functions for Safety-Critical Continuous Control Tasks

2019 ◽  
Vol 33 ◽  
pp. 3387-3395 ◽  
Author(s):  
Richard Cheng ◽  
Gábor Orosz ◽  
Richard M. Murray ◽  
Joel W. Burdick
Keyword(s):  
Reinforcement Learning ◽  
System Dynamics ◽  
Learning Process ◽  
High Performance ◽  
Continuous Control ◽  
Barrier Functions ◽  
Synthesis Algorithm ◽  
Vehicle Communication ◽  
Model Free ◽  
Vehicle To Vehicle

Reinforcement Learning (RL) algorithms have found limited success beyond simulated applications, and one main reason is the absence of safety guarantees during the learning process. Real world systems would realistically fail or break before an optimal controller can be learned. To address this issue, we propose a controller architecture that combines (1) a model-free RL-based controller with (2) model-based controllers utilizing control barrier functions (CBFs) and (3) online learning of the unknown system dynamics, in order to ensure safety during learning. Our general framework leverages the success of RL algorithms to learn high-performance controllers, while the CBF-based controllers both guarantee safety and guide the learning process by constraining the set of explorable polices. We utilize Gaussian Processes (GPs) to model the system dynamics and its uncertainties. Our novel controller synthesis algorithm, RL-CBF, guarantees safety with high probability during the learning process, regardless of the RL algorithm used, and demonstrates greater policy exploration efficiency. We test our algorithm on (1) control of an inverted pendulum and (2) autonomous carfollowing with wireless vehicle-to-vehicle communication, and show that our algorithm attains much greater sample efficiency in learning than other state-of-the-art algorithms and maintains safety during the entire learning process.

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