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In the last years the use of Ethernet as the communication technology for automation systems has been sensibly increasing. In particular, Real-Time Ethernet networks have become widely adopted. In this paper we consider one of the most popular Real-Time Ethernet networks, namely EtherCAT. We firstly provide a short outline of the protocol, along with a description of a simulation model we have developed. Subsequently, we focus on some typical network configurations and provide some insights on their performance by means of both theoretical analysis and numerical simulations.

We study a problem of output feedback stabi-lization of complex-valued reaction-advection-diffusion systems with parametric uncertainties (these systems can also be viewedas coupled parabolic PDEs). Both sensing and actuation are performed at the boundary of the PDE domain and the unknown parameters are allowed to be spatially varying. First, we transform the original system into the form where unknown functional parameters multiply the output, which can be viewed as a PDE analog of observer canonical form. Input and output filters are then introduced to convert a dynamic parametrization of the problem into a static parametrization where a gradient estimation algorithm is used. The control gain is obtained by solving a simple complex-valued integral equation online. The solution of the closed-loop system is shown to be bounded and asymptotically stable around the zero equilibrium. The results are illustrated by simulations.

The paper deals with the Model Predictive Control(MPC) algorithm applied to control a permanent magnet synchronous motor, which is, at present, among the motors with the highest power efficiency and then very attractive for energy-saving applications. Absolute novelty of the proposed MPC is its feature of inherently managing the flux weakening control above base speed.Speed and current controller are combined together, including all the state variables of the system, instead of keeping the conventional cascade structure. This way it is possible to enforce in the controller the current and voltage limits. Simulation and experimental results point out the validity of the design procedure and the powerful capabilities of the MPC in the electrical drives field.

In this paper we study the problem of estimatingthe channel parameters for a generic wireless sensor network(WSN) in a completely distributed manner, using consensusalgorithms. Specifically, we first propose a distributed strategyto minimize the effects of unknown constant offsets in thereading of the Radio Strength Signal Indicator (RSSI) due touncalibrated sensors. Then we show how the computation of theoptimal wireless channels parameters, which are the solutionof a global least-square optimization problem, can be obtainedwith a consensus-based algorithm. The proposed algorithmsare general algorithms for sensor calibration and distributedleast-square parameter identification, and do not require anyknowledge on the global topology of the network nor thetotal number of nodes. Finally, we apply these algorithms toexperimental data collected from an indoor WSN.

A detailed study of position changes of plasma strike points before and after edge localized modes (ELMs) in JET was carried out. A hypothesis being tested is that in an ELM previously closed edge field lines would open up, releasing plasma current and leading to the formation of a new, smaller separatrix. It was observed that after each ELM strike points have shifted a few centimetres towards the plasma centre (up in JET). In some cases a transient (<100?µs), upwards large (>10?cm) jump of strike positions was observed first. It was followed by an equally fast jump down to the shifted strike positions. Such behaviour has not been described in previous computational models of the ELM. Therefore two novel instability mechanisms are presented, which contribute to explain the changes in strike point position: an X-point instability, due to positive toroidal current density at the X-point, and a diamagnetic instability, due to negative inboard toroidal current density.

Recently, two new types of communication networks have become available at the low levels of factory automation systems. Besides fieldbuses, which have been traditionally used since long time, both Real–Time Ethernet (RTE) and wireless networks may now be employed. Consequently, it is envisaged that hybrid configurations using all types of the available communication systems will be even more deployed in the future. In this paper we focus, specifically, on hybrid systems which realize wireless extensions of wired networks. In detail, we address the extension of Ethernet Powerlink, a popular RTE network, by means of the IEEE 802.11 WLAN. We consider two types of extensions based on both bridge and gateway devices. After a discussion concerning the actual implementation of the extensions, we provide some performance figures obtained from both a theoretical analysis and numerical simulations.