Search results for "Real-time Control System"

Schedulability analysis of window-constrained execution time tasks for real-time control

2003

Feasibility tests for hard real-time systems provide information about the schedulability of a set of tasks. However, this information is a yes or no answer whether the task set achieves the test or not. From the system design point of view, it would be useful to have more information, for example, how much can one vary some task parameters, such as computation time, without jeopardizing the system feasibility. The aim of the work is to provide a method to determine how much a task can increase its computation time, maintaining the system feasibility under a dynamic priority scheduling. This extra time can be determined not only in all the task activations, but in n of a window of m task in…

FPGA-based concurrent watchdog for real-time control systems

2003

A straightforward and efficient implementation of a custom concurrent watchdog processor for real-time control systems is presented. Emphasis is given to the techniques used for on-line checking the main processor activity without adding overhead, and to the advantages of a field programmable gate array implementation.

Network and System Performance Management for Next Generation Networks

2006

The physical and logical structures of next generation network and service environment is complex and requires increasingly sophisticated and complicated tools to be fully controllable and well managed. The main problem that has risen is that the old telemanagement model has not enough flexibility to manage rapidly and constantly changing network environment. 3G and 4G networks are basically IP based and the knowledge of IP type traffic management is somewhat new and challenging to telecom vendors. The present way of controlling and managing telecom systems is to use Non Real Time off-line PM (Performance Monitoring) and tools. Time periods between tuning can now be some days to some weeks …

Integrating Manufacturing Equipments Using a Shop Floor Control System

2006

A generic manufacturing system must interact with an environment characterized by a strong competition and by continuous technological changes. For this reason there is the necessity to make the system easily and economically modifiable in its hardware and software configuration. One of the main problems in making a manufacturing system re-configurable concerns its control system which has to be accordingly scalable and object oriented. This paper presents a methodology for making a manufacturing control system actually reconfigurable and adaptable to hardware changes in the manufacturing systems components. In particular, a PC-based shop-floor control system has been realized. Such system …

Experimental investigation on high efficiency real-time control algorithms for IPMSMs

2014

This paper describes an experimental investigation on the power losses variations occurring in an Interior Permanent Magnet Synchronous Motor (IPMSM) with respect to the direct axis current component. Such investigation can be useful to determine a mathematical model accounting for copper, iron and mechanical friction losses, and for the arrangement of a speed control drive system equipped with a real-time power losses minimization algorithm. In particular, a test bench has been set up in order to carry out all measurements and the final power loss identification. The test bed is composed by a IPMSM drive with a field oriented control (FOC) strategy, a power analyzer, a dynamometric brake a…

A new ifierarchical and intelligent control architecture based on distributed neural networks and expert systems applied to vehicle automation

2005

Controlling Domains with High Levels of Hysteresis Using Qualitative Modelling

1997

Abstract Dans ce papier, on se propose I'architecture d'un systeme expert pour controle a temps reel basee sur un modele qualitatif- Le susteme de controle utilise le modele qualitatif pour predire problemes futures et pour manier dounees incompletes et imprecises des sensors. Cettes habilites sout tres precieses pour controler systemes avec une grande niveau d'hysteresis, et foumissent un controle doux et rapide. Nous avans applique l'architecture proposee a le domaine du control de trafic urbain, caracterise par grandes problemes d'hysteresis.

Real-time Control of Metallurgic Processes

1996

The careful control of the liquid metal solidification and the solid shell growth is of central importance in all metallurgic processes. These have a considerable influence on the formation of cracks and other defects which can be formed in the cast material. To ensure defect free products, the liquid metal is to be cooled down according to a pattern which depends i.e. on metal grade, product dimension, cooling speed and machine design. On the other hand, the control of the liquid/solid interface is a key element in optimising the liquid solidification with respect to good productivity. So, the heat transfer plays a very important role in metallurgic casting processes, especially when casti…