scholarly journals Scheduling Optimization of Time-Triggered Cyber-Physical Systems Based on Fuzzy-Controlled QPSO and SMT Solver

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 668
Author(s):  
Jie Jian ◽  
Lide Wang ◽  
Huang Chen ◽  
Xiaobo Nie
Keyword(s):  
Scheduling Algorithm ◽  
Cyber Physical Systems ◽  
Satisfiability Modulo Theories ◽  
Random Mutation ◽  
Physical Systems ◽  
Smt Solver ◽  
Time Requirements ◽  
Adaptive Adjustment ◽  
Periodic Traffic ◽  
Cost Efficient

The time-triggered communication paradigm is a cost-efficient way to meet the real-time requirements of cyber-physical systems. It is a non-deterministic polynomial NP-complete problem for multi-hop networks and non-strictly periodic traffic. A two-level scheduling approach is proposed to simplify the complexity during optimization. In the first level, a fuzzy-controlled quantum-behaved particle swarm optimization (FQPSO) algorithm is proposed to optimize the scheduling performance by assigning time-triggered frame instances to the basic periods of each link. In order to prevent population from high aggregation, a random mutation mechanism is used to disturb particles at the aggregation point and enhance the diversity at later stages. Fuzzy logic is introduced and well designed to realize a dynamic adaptive adjustment of the contraction–expansion coefficient and mutation rate in FQPSO. In the second level, we use an improved Satisfiability Modulo Theories (SMT) scheduling algorithm to solve the collision-free and temporal constraints. A schedulability ranking method is proposed to accelerate the computation of the SMT-based incremental scheduler. Our approach can co-optimize the jitter and load balance of communication for an off-line schedule. The experiments show that the proposed approach can improve the performance of the scheduling table, reduce the optimization time, and reserve space for incremental messages.

scholarly journals Identifying Promising Application Areas for Cyber-Physical and Complex Event Processing in Logistics Practice

Logistics ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 23
Author(s):  
Cyril Alias ◽  
Frank Alarcón Olalla ◽  
Hauke Iwersen ◽  
Julius Ollesch ◽  
Bernd Noche
Keyword(s):  
Cyber Physical Systems ◽  
Complex Event Processing ◽  
Event Processing ◽  
Use Case ◽  
Logistics Industry ◽  
Physical Systems ◽  
Case Examples ◽  
Promising Application ◽  
Cost Efficient ◽  
Huge Challenge

In the course of the ongoing era of digitization, cyber-physical systems and complex event processing belong to the most discussed technologies nowadays. The huge challenge that digitization is forming to the transportation and logistics sector is largely accepted by the responsible organizations. Despite initial steps being taken towards digitized value-creation, many professionals wonder about how to realize the ideas and stumble with the precise steps to be taken. With the vision of smart logistics in mind and cost-efficient technologies available, they require a systematic methodology to exploit the potentials accompanying digitization. With the help of an effective and targeted workshop procedure, potentially appropriate application areas with promising benefit potentials can be identified effectively. Such a workshop procedure needs to be a stepwise approach in order to carefully consider all the relevant aspects and to allow for organizational acceptance to grow. In three real-world use case examples from different areas of the transportation and logistics industry, promising applications of cyber-physical systems and complex event processing are identified and pertaining event patterns of critical situations developed in order to make realization easier at a later stage. Each use case example exhibits a frequently occurring problem that can be effectively addressed by using the above-mentioned technology.

Functional verification of cyber-physical systems containing machine-learnt components

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Farzaneh Moradkhani ◽  
Martin Fränzle
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Neural Networks ◽  
Cyber Physical Systems ◽  
Satisfiability Modulo Theories ◽  
Activation Functions ◽  
Physical Systems ◽  
Smt Solvers ◽  
Non Linear ◽  
Artificial Neural

Abstract Functional architectures of cyber-physical systems increasingly comprise components that are generated by training and machine learning rather than by more traditional engineering approaches, as necessary in safety-critical application domains, poses various unsolved challenges. Commonly used computational structures underlying machine learning, like deep neural networks, still lack scalable automatic verification support. Due to size, non-linearity, and non-convexity, neural network verification is a challenge to state-of-art Mixed Integer linear programming (MILP) solvers and satisfiability modulo theories (SMT) solvers [2], [3]. In this research, we focus on artificial neural network with activation functions beyond the Rectified Linear Unit (ReLU). We are thus leaving the area of piecewise linear function supported by the majority of SMT solvers and specialized solvers for Artificial Neural Networks (ANNs), the successful like Reluplex solver [1]. A major part of this research is using the SMT solver iSAT [4] which aims at solving complex Boolean combinations of linear and non-linear constraint formulas (including transcendental functions), and therefore is suitable to verify the safety properties of a specific kind of neural network known as Multi-Layer Perceptron (MLP) which contain non-linear activation functions.

scholarly journals SMT-Based CPS Parameter Synthesis

10.29007/msr8 ◽  
2018 ◽  
Author(s):  
Heinz Riener ◽  
Robert Koenighofer ◽  
Goerschwin Fey ◽  
Roderick Bloem
Keyword(s):  
Cyber Physical Systems ◽  
Satisfiability Modulo Theories ◽  
Proof Of Concept ◽  
Physical Systems ◽  
Inductive Synthesis ◽  
Parameter Synthesis ◽  
Guided Inductive

We present a simple, yet flexible parameter synthesis and repair approach for Cyber-Physical Systems (CPS). The user defines the behavior of a CPS, a set of (un)safe states, and a generic template for an inductive invariant using Satisfiability Modulo Theories (SMT) formulas. Counterexample-Guided Inductive Synthesis (CEGIS) is then used to compute values for open parameters and a concrete invariant to prove that all unsafe states are unreachable. Using templates for expressions, the approach can also be used for CPS repair. We present a proof-of-concept tool, optimizations, and first experiments.

scholarly journals Modeling Time Requirements of CPS in Wireless Networks

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1818 ◽  
Author(s):  
César Huegel Richa ◽  
Mateus M. de Lucena ◽  
Leonardo Passig Horstmann ◽  
José Luis Conradi Hoffmann ◽  
Antônio Augusto Fröhlich
Keyword(s):  
Case Analysis ◽  
Network Capacity ◽  
Cyber Physical Systems ◽  
Worst Case Analysis ◽  
Worst Case ◽  
Physical Systems ◽  
Network Load ◽  
Time Requirements ◽  
Safety Parameter ◽  
Margin Of Safety

In this paper, we present an approach to assess the schedulability and scalability of Cyber-Physical Systems (CPS) Networks through an algorithm that is capable of estimating the load of the network as its utility grows. Our approach evaluates both the network load and the laxity of messages, considering its current topology and real-time constraints while abstracting environmental specificities. The proposed algorithm also accounts for the network unreliability by applying a margin-of-safety parameter. This approach enables higher utilities as it evaluates the load of the network considering a margin-of-safety that encapsulates phenomena such as collisions and interference, instead of performing a worst-case analysis. Furthermore, we present an evaluation of the proposed algorithm over three representative scenarios showing that the algorithm was able to successfully assess the network capacity as it reaches a higher use.

Emerging Cyber-Physical Systems : An Overview

2018 ◽  
pp. 306-316
Author(s):  
Okolie S.O. ◽  
Kuyoro S.O. ◽  
Ohwo O. B
Keyword(s):  
Health Care ◽  
Economic Benefit ◽  
Physical World ◽  
Cyber Physical Systems ◽  
Cyber Physical System ◽  
Economic Sectors ◽  
Strategic Research ◽  
Physical Systems ◽  
Security Issues ◽  
Wide Range

Cyber-Physical Systems (CPS) will revolutionize how humans relate with the physical world around us. Many grand challenges await the economically vital domains of transportation, health-care, manufacturing, agriculture, energy, defence, aerospace and buildings. Exploration of these potentialities around space and time would create applications which would affect societal and economic benefit. This paper looks into the concept of emerging Cyber-Physical system, applications and security issues in sustaining development in various economic sectors; outlining a set of strategic Research and Development opportunities that should be accosted, so as to allow upgraded CPS to attain their potential and provide a wide range of societal advantages in the future.

Sign in / Sign up

Export Citation Format

Share Document