Pasquale Arpaia, Mario Girone, Domenico Maisto, Carlo Manna, Marco Pezzetti
Generalized extremal optimization of predictive maintenance to enhance monitoring of large experimental systems

Predictive maintenance scheduling is an optimization problem aimed at defining the best activity sequence to minimize the expected cost over a time horizon. For very-large systems such as in experimental physics, maintenance optimization turns out to be very difficult owing to analytically intractable objective functions. In this paper, a meta-heuristic predictive maintenance algorithm based on the Generalized Extremal Optimization (GEO) is presented. With respect to state-of-the-art meta-heuristic techniques, the GEObased maintenance algorithm allows optimization procedure to be configured easily through only one parameter without a numerous population. Preliminary results of the algorithm performance validation on the liquid helium storage system of the Large Hadron Collider at CERN are reported.

H. Braun, M. Buzio, R. Deckardt, O. Dunkel, R. Felder, L. Fiscarelli, R. Ganter, S. Kasaei, F. Löhl, S. Sanfilippo, G. Severino, V. Vrankovic, L. Walckiers
Small-diameter rotating coils for field quality measurements in quadrupole magnets

Two rotating coil shafts with a challenging small diameter of 8 and 19 mm, originally developed at CERN for the measurement of linear accelerator magnets, have been used to quantify the magnetic field strength, the harmonic content and the field direction of series quadrupoles for the Swiss Free Electron Laser in construction at the Paul Scherrer Institute. In this paper, we describe the design and construction of these coils, the procedure used for their calibration, and the results obtained on the magnets tested so far. We focus especially on the manufacturing and calibration difficulties related to the very small diameter of these coils, which makes it challenging to obtain relative errors at the level of a few 10-4 as it is commonly required by accelerator beam optics. The last part of the paper is dedicated to a selection of measurement results obtained on Swiss Free Electron Laser quadrupoles to illustrate the performance of the two types of coils on series measurements.

Giancarlo Golluccio, Anthony Beaumont, Marco Buzio, Olaf Dunkel, Markus Stockner, Thomas Zickler
PCB coil array for measuring curved accelerator dipoles: two case studies on the MedAustron accelerator

Printed Circuit Boards (PCB) are largely used as measurement devices. Recently they have found applications in magnetic field measurements of accelerator magnets, in particular in rotating coil system, thanks to the quality that can be achieved in terms of coil area and winding distribution. In this paper the application of such technology to produce an array of coils for measuring the integral field homogeneity inside curved accelerator dipole magnets is presented. A set of static coils measuring the flux variations during a current pulse, which are installed on parallel paths of the particle trajectory, is the so-called “fluxmeter”. After an introduction to the challenges to face in measuring large curved dipoles, we describe the measurement requirements and constraints, required by the MedAustron accelerators synchrotron and high energy transfer line dipoles. In the second part, the design and technical details of the PCB and the whole fluxmeter structure are reported. The last section is dedicated to the method used for the relative calibration of the coils and the results.

Antonio Affanni, Giovanni Chiorboli
Wearable Instrument for Skin Potential Response Analysis in AAL applications

A novel instrument able to acquire Skin Potential Response (SPR) signals is proposed; SPR is a branch of Electrodermal Activity (EDA) and consists of reading nervous electric pulses that arise when the sympathetic nervous system activates sweat glands as a reaction of an external stressing stimulus. Scientific literature shows that EDA is a good methodology to detect workload, increased stress level and many neurological diseases or addictions. In this paper, we present the design and characterization of a wearable, battery operated, wireless device which can acquire SPR data and can be integrated in a wireless sensor network for the AAL. The developed control panel is responsible of receiving the SPR data, plotting them in real time and, on a secondary screen, providing to the patient visual and auditory stimuli; as a further stimuli generator, an adaptive game controlled by the SPR signal has been developed. The synchronous plot of stimuli markers and SPR signal on the same graph can provide a very useful information for the SPR analysis.

Stefano Scheggi, Marco Aggravi, Domenico Prattichizzo
A vibrotactile bracelet to improve the navigation of older adults in large and crowded environments

The decline of the cognitive abilities related to age usually determines a gradual withdrawal of older adults within the domestic walls. Part of the problem is the difficulty in navigating in large and crowded environments thatmay be perceived as intimidating. To alleviate this problem, we propose a vibrotactile device which can be used along with a walking assistant endowed with autonomous sensing and active brakes able to guide the user. In this paper, we address the problem of guiding the user with a minimal impact on his/her freedom of motion. We propose a solution based on the use of vibrotactile feedback to display directional cues. Psychophysical tests performed on a group of older adults show the effectiveness of the proposed vibrotactile strategy for the navigation of elderly people.