Recent EUROfusion Achievements in Support of Computationally Demanding Multiscale Fusion Physics Simulations and Integrated Modeling

Integrated modeling (IM) of present experiments and future tokamak reactors requires the provision of computational resources and numerical tools capable of simulating multiscale spatial phenomena as well as fast transient events and relatively slow plasma evolution within a reasonably short computational time. Recent progress in the implementation of the new computational resources for fusion applications in Europe based on modern supercomputer technologies (supercomputer MARCONI-FUSION), in the optimization and speedup of the EU fusion-related first-principle codes, and in the development of a basis for physics codes/modules integration into a centrally maintained suite of IM tools achieved within the EUROfusion Consortium is presented. Physics phenomena that can now be reasonably modelled in various areas (core turbulence and magnetic reconnection, edge and scrape-off layer physics, radio-frequency heating and current drive, magnetohydrodynamic model, reflectometry simulations) following successful code optimizations and parallelization are briefly described. Development activities in support to IM are summarized. They include support to (1) the local deployment of the IM infrastructure and access to experimental data at various host sites, (2) the management of releases for sophisticated IM workflows involving a large number of components, and (3) the performance optimization of complex IM workflows.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014 to 2018 under grant agreement 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission or ITER.Peer ReviewedPostprint (published version

Variable structure robot control systems: The RAPP approach

International audienceThis paper presents a method of designing variable structure control systems for robots. As the on-board robot computational resources are limited, but in some cases the demands imposed on the robot by the user are virtually limitless, the solution is to produce a variable structure system. The task dependent part has to be exchanged, however the task governs the activities of the robot. Thus not only exchange of some task-dependent modules is required, but also supervisory responsibilities have to be switched. Such control systems are necessary in the case of robot companions, where the owner of the robot may demand from it to provide many services.

Asynchronous data flow handling in component-based robot perception subsystems

Obsługa asynchronicznego przepływu danych w złożonych potokach obliczeniowych, jakie z reguły tworzą podsystemy sensoryczne robotów, wymaga wytworzenia odpowiednich narzędzi wspomagających ich implementację. W artykule zaproponowano rozwiązanie umożliwiające warunkowe działanie poszczególnych bloków obliczeniowych w zależności od dostępnych danych. Rozważania teoretyczne doprowadziły do implementacji tych mechanizmów w strukturze ramowej DisCODe. Działanie rozwiązania przedstawiono na dwóch prostych przykładach.Handling of asynchronous data flows in complex computational systems such as robot sensor subsystems requires appropriate tools facilitating their implementation. The article proposes a solution to the aforementioned problem. The solution enables the activation of a conditional behaviour of the individual computational blocks, depending on the presence of data in their input buffers. Theoretical considerations led to the implementation of these mechanisms in a component-oriented framework for development of diverse robot perception subsystems: DisCODe. Operation of the solution is illustrated in two simple exemplary tasks

Model samolotu bezzałogowego dla analizy i syntezy rekonfiguracji układu sterowania

Reliability of unmanned aircraft is a decisive factor for conducting air tasks in a controlled airspace. One of the means of improving unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite an occurring failure. The control system is reconfigured by using still operational control surfaces to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which each control surface deflection can be controlled independently. The paper describes anon-linear model of a small unmanned aircraft with decoupled control surfaces. The paper discusses aircraft flight dynamics equations and estimated equations for controllability derivatives for each control surface, the results of comparison tests of the model and actual aircraft as well as the structure of the simulation model. The developed unmanned aircraft model may be used in development and in optimization of control algorithms for aircraft with damaged control systems as well as to test the impact of failures on dynamic properties of the aircraft.Niezawodność samolotów bezzałogowych jest czynnikiem decydującym o możliwości wykonywania zadań lotniczych w: kontrolowanej przestrzeni powietrznej. Jedną z metod zwiększenia niezawodności samolotów bezzałogowych jest rekonfiguracja układu sterowania., która umożliwia sterowanie samolotem pomimo powstałej awarii. Rekonfiguracja systemu sterowania polega na wykorzystaniu sprawnych powierzchni sterowych do kompensacji skutków awarii oraz sterowania uszkodzonym samolotem. Opracowanie efektywnych algorytmów rekonfiguracji wymaga wykorzystania nieliniowego modelu dynamiki samolotu bezzałogowego, w którym możliwe jest niezależne sterowanie wychyleniem każdej powierzchni sterowej. W pracy przedstawiono nieliniowy model małego samolotu bezzałogowego o rozprzężonych powierzchniach sterowych. Przestawiono równania dynamiki samolotu oraz oszacowane równania pochodnych sterowności dla każdej z powierzchni sterowych, wyniki testów porównawczych modelu i rzeczywistego samolotu oraz strukturę modelu symulacyjnego. Opracowany model samolotu bezzałogowego może być wykorzystany do opracowania oraz optymalizacji algorytmów sterowania samolotem z uszkodzonym systemem sterowania, oraz badania wpływu awarii na właściwości dynamiczne samolotu

Agent-based approach to the design of a multimodal interface for cyber-security event visualisation control

Convenient human-computer interaction is essential to carry out many exhausting and concentration-demanding activities. One of them is cyber-situational awareness as well as dynamic and static risk analysis. A specific design method for a multimodal human-computer interface (HCI) for cyber-security events visualisation control is presented. The main role of the interface is to support security analysts and network operators in their monitoring activities. The proposed method of designing HCIs is adapted from the methodology of robot control system design. Both kinds of systems act by acquiring information from the environment, and utilise it to drive the devices influencing the environment. In the case of robots the environment is purely physical, while in the case of HCIs it encompasses both the physical ambience and part of the cyber-space. The goal of the designed system is to efficiently support a human operator in the presentation of cyberspace events such as incidents or cyber-attacks. Especially manipulation of graphical information is necessary. As monitoring is a continuous and tiring activity, control of how the data is presented should be exerted in as natural and convenient way as possible. Hence two main visualisation control modalities have been assumed for testing: static and dynamic gesture commands and voice commands, treated as supplementary to the standard interaction. The presented multimodal interface is a component of the Operational Centre, which is a part of the National Cybersecurity Platform. Creation of the interface out of embodied agents proved to be very useful in the specification phase and facilitated the interface implementation