A review of multi-car elevator system

This paper presents a review of a new generation of elevator system, the Multi-Car Elevator System. It is an elevator system which contains more than one elevator car in the elevator shaft. In the introduction, it explains why the Multi-Car Elevator System is a new trend elevator system based on its structural design, cost saving and efficiency in elevator system. Different types of Multi-Car Elevator System such as circulation or loop-type, non-circulation and bifurcate circulation are described in section 2. In section 3, researches on dispatch strategies, control strategies and avoidance of car collision strategies of Multi-Car Elevator System since 2002 are reviewed. In the discussion section, it reveals some drawbacks of the Multi-Car Elevator System in transport capability and the risk of car collision. There are recommendations to the future work as well

Eighth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools, Aarhus, Denmark, October 22-24, 2007

This booklet contains the proceedings of the Eighth Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 22-24, 2007. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop0

Animation-based validation of reactive software systems using behavioural models

Tese de doutoramento em InformáticaDuring the development of software systems, validation is a crucial activity to guarantee that the software system ful lls the users' needs and expectations. A key issue to have a successful validation consists in adopting a process where users and clients can actively discuss the requirements of the system under development. A reactive system is expected to continuously interact with its environment. Usually, the interaction of a reactive system with its environment is supported by a set of nonterminating processes that operate in parallel. During the interaction, the reactive system must answer to high-priority events, even when the system is executing something else. Due to above characteristics, the behaviour of reactive systems can be very complex. The approach suggested in this thesis assumes that the requirements of reactive software systems are partially described by use case diagrams, and each use case is detailed by a collection of scenario descriptions. Within this approach, one can obtain, from a set of behavioural scenarios of a given system, an executable behavioural model that can support, when complemented with animation- and domain-speci c elements, a graphical animation for reproducing that set of scenarios for validation purposes. Animating the scenarios using graphical elements from the application domain ensures an e ective involvement of the users in the system's validation. The Coloured Petri nets (CPNs) modelling language is used as the notation to obtain the behavioural models, due to its natural support for mechanisms like concurrency, synchronisation, and resource sharing and its tool support. The obtained CPN model is guaranteed to be (1) parametric, allowing an easy modi cation of the initial conditions of the scenarios, (2) environment-descriptive, meaning that it includes the state of the relevant elements of the environment, and (3) animation-separated, implying that the elements related to the animation are separated from the other ones. We validate our approach based on its application to three case studies of reactive systems.Durante o desenvolvimento de sistemas de software, a validação é uma actividade crucial para garantir que o sistema de software satisfaz as necessidades e expectativas do utilizador. O sucesso na validação consiste na utilização de um processo onde os utilizadores e os clientes possam discutir de uma forma activa os requisitos do sistema que está a ser desenvolvido. Um sistema reactivo está continuamente em interacção com o seu ambiente, que é geralmente suportada por um conjunto de processos intermináveis que operam em paralelo. Durante a interacção, o sistema reactivo dever a responder aos eventos com alta prioridade, mesmo quando o sistema está a executar algo diferente. Devido às características anteriores, o comportamento dos sistemas reactivos pode ser muito complexo. A abordagem sugerida nesta tese assume que os requisitos de sistemas reactivos são em parte descritos por diagramas de casos de uso e que cada caso de uso é detalhado por uma colecção de descrições de cenários. Nesta abordagem, é possível obter, a partir de um conjunto de cenários de um dado sistema, um modelo comportamental que seja executável e que suporte, quando complementado com elementos específicos, uma animação gráfica que reproduza aquele conjunto de cenários para fins de validação. A animação dos cenários utilizando elementos gráficos do domínio da aplicação garante um envolvimento efectivo dos utilizadores na validação do sistema. A linguagem de modelação redes de Petri coloridas (CPNs) é usada como a notação para obter os modelos comportamentais, devido ao seu suporte natural a mecanismos como a concorrência, sincronização e partilha de recursos, e às suas ferramentas de suporte. Se as recomendações da abordagem proposta foram seguidas, temos a garantia que o modelo CPN: (1) parametriza as condições iniciais dos cenários, (2) contém uma descrição do ambiente, incluindo o estado dos seus elementos, e (3) separa os elementos relacionados com a animação dos outros elementos do modelo. A validação da nossa abordagem tem por base a sua aplicação a três casos de estudo de sistemas reactivos.Fundação para a Ciência e a Tecnologia (FCT) SFRH/BD/19718/200

Explicit/multi-parametric Moving Horizon Estimation and Model Predictive Control & their Application to Small Unmanned Aerial Vehicles

Moving horizon estimation (MHE) is a class of estimation methods in which the system state and disturbance estimates are obtained by solving a constrained optimization problem. The main advantage of MHE is that information about the system can be explicitly considered in the form of constraints and hence improve the estimates. In stochastic systems the estimation error will inevitably be non-zero and the controller needs to explicitly account for it to prevent constraint violations. In order for the controller to be robustified against the estimation error, bounds on the error need to be known. These bounds can be calculated if the dynamics that govern the estimation error are known. This work presents those dynamics for the unconstrained and the constrained case of the moving horizon estimator with a linear time-invariant model, and also discusses how the bounds on the estimation error can be obtained with set-theoretical methods. Those bounds are then used for robust output-feedback model predictive control (MPC). The MHE and the MPC are derived explicitly through multi-parametric programming. The complete framework is demonstrated using simultaneous MHE and tubebased MPC. The possibility of solving MPC explicitly is very appealing for flight control of small unmanned aerial vehicles (UAVs) because the behaviour of the controller is known in advance and can be guaranteed. Flight control is a challenging task that involves a multi-layer control structure where each decision influences the other layers and the overall performance. This work investigates the requirements on the different layers and their cross-effects. A linear model of the UAV is derived such that it captures the wind which is the most challenging disturbance for UAV flight. Particular focus is placed on the design of a model predictive controller as the autopilot and on in-flight wind estimation

ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017

Advances in Reinforcement Learning

Reinforcement Learning (RL) is a very dynamic area in terms of theory and application. This book brings together many different aspects of the current research on several fields associated to RL which has been growing rapidly, producing a wide variety of learning algorithms for different applications. Based on 24 Chapters, it covers a very broad variety of topics in RL and their application in autonomous systems. A set of chapters in this book provide a general overview of RL while other chapters focus mostly on the applications of RL paradigms: Game Theory, Multi-Agent Theory, Robotic, Networking Technologies, Vehicular Navigation, Medicine and Industrial Logistic

EG-ICE 2021 Workshop on Intelligent Computing in Engineering

The 28th EG-ICE International Workshop 2021 brings together international experts working at the interface between advanced computing and modern engineering challenges. Many engineering tasks require open-world resolutions to support multi-actor collaboration, coping with approximate models, providing effective engineer-computer interaction, search in multi-dimensional solution spaces, accommodating uncertainty, including specialist domain knowledge, performing sensor-data interpretation and dealing with incomplete knowledge. While results from computer science provide much initial support for resolution, adaptation is unavoidable and most importantly, feedback from addressing engineering challenges drives fundamental computer-science research. Competence and knowledge transfer goes both ways