Juan Manuel López

Implementation of the Disruption Predictor APODIS in JET’s Real-Time Network Using the MARTe Framework

This paper describes the implementation of a real-time disruption predictor that is based on support vector machine (SVM) classifiers. The implementation was performed under the MARTe framework on a six-core x86 architecture. The system is connected via JETs Real-time Data Network (RTDN). The online results show a high degree of successful predictions and a low rate of false alarms, thus confirming the usefulness of this approach in a disruption mitigation scheme. The implementation shows a low computational load, which will be exploited in the immediate future to increase the predictions temporal resolution.

Engineering design of ITER prototype Fast Plant System Controller

The ITER control, data access and communication (CODAC) design team identified the need for two types of plant systems. A slow control plant system is based on industrial automation technology with maximum sampling rates below 100 Hz, and a fast control plant system is based on embedded technology with higher sampling rates and more stringent real-time requirements than that required for slow controllers. The latter is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and, if necessary, high performance networks. Two prototypes of a fast plant system controller specialized for data acquisition and constrained by ITER technological choices are being built using two different form factors. This prototyping activity contributes to the Plant Control Design Handbook effort of standardization, specifically regarding fast controller characteristics. Envisaging a general purpose fast controller design, diagnostic use cases with specific requirements were analyzed and will be presented along with the interface with CODAC and sensors. The requirements and constraints that real-time plasma control imposes on the design were also taken into consideration. Functional specifications and technology neutral architecture, together with its implications on the engineering design, were considered. The detailed engineering design compliant with ITER standards was performed and will be discussed in detail. Emphasis will be given to the integration of the controller in the standard CODAC environment. Requirements for the EPICS IOC providing the interface to the outside world, the prototype decisions on form factor, real-time operating system, and high-performance networks will also be discussed, as well as the requirements for data streaming to CODAC for visualization and archiving.

A new 3D finite element model of the IEC 60318-1 artificial ear

The artificial ear specified in IEC 60318-1 is used for the measurement of headphones and has been designed to present an acoustic load equivalent to that of normal human ears. In this respect it is specified in terms of an acoustical impedance, and modelled by a lumped parameter approach. However, this has some inherent frequency limitations and becomes less valid as the acoustic wavelength approaches the characteristic dimensions within the device. In addition, when sound propagates through structures such as narrow tubes, annular slits or over sharp corners, noticeable thermal and viscous effects take place causing further departure from the lumped parameter model. A new numerical model has therefore been developed, which gives proper consideration to the aforementioned effects. Both kinds of losses can be simulated by means of the LMS Virtual Lab acoustic software which facilitates finite and boundary element modelling of the whole artificial ear. A full 3D model of the artificial ear has therefore been developed based on key dimensional data found in IEC 60318-1. The model has been used to calculate the acoustical impedance, and the results compared with the corresponding data determined from the lumped parameter model. The numerical simulation of the artificial ear has been shown to provide realistic results, and is a powerful tool for developing a detailed understanding of the device. It is also proving valuable in the revision of IEC 60318-1 that is currently in progress.

ITER prototype fast plant system controller based on ATCA platform

The ITER Fast Plant System Controllers (FPSC) are based on embedded technologies and will be devoted to both data acquisition tasks (sampling rates >1 kSPS) and control purposes in closed-control loops whose cycle times are below 1 ms. Fast Controllers will be dedicated industrial controllers with the ability to: i) supervise other fast and/or slow controllers; ii) interface to actuators and sensors and high performance networks. This contribution presents an FPSC prototype, specialized for data acquisition, based on the ATCA (Advanced Telecommunications Computing Architecture) standard. This prototyping activity contributes to the ITER Plant Control Design Handbook (PCDH) effort of standardization, specifically regarding fast controller characteristics. For the prototype, IPFN is developing a new family of ATCA modules targeting ITER requirements. The modules comprise an AMC carrier/data hub/timing hub compliant with the upcoming ATCA extensions for Physics and a multi-channel with galvanic isolation hot-swappable digitizer designed for serviceability. The design and test of a peer-to-peer communications layer for the implementation of a reflective memory over PCI Express and the design and test of an IEEE-1588 transport layer over a high performance serial link was also performed. In this work, a complete description of the solution is presented as well as the integration of the controller into the standard CODAC environment. The most relevant results of real tests will be addressed, focusing in the benefits and limitations of the applied technologies.

A new 3D finite element model of the IEC 60318-1 artificial ear: II. Experimental and numerical validation

In part I, the feasibility of using three-dimensional (3D) finite elements (FEs) to model the acoustic behaviour of the IEC 60318-1 artificial ear was studied and the numerical approach compared with classical lumped elements modelling. It was shown that by using a more complex acoustic model that took account of thermo-viscous effects, geometric shapes and dimensions, it was possible to develop a realistic model. This model then had clear advantages in comparison with the models based on equivalent circuits using lumped parameters. In fact results from FE modelling produce a better understanding about the physical phenomena produced inside ear simulator couplers, facilitating spatial and temporal visualization of the sound fields produced.The objective of this study (part II) is to extend the investigation by validating the numerical calculations against measurements on an ear simulator conforming to IEC 60318-1. For this purpose, an appropriate commercially available device is taken and a complete 3D FE model developed for it. The numerical model is based on key dimensional data obtained with a non-destructive x-ray inspection technique. Measurements of the acoustic transfer impedance have been carried out on the same device at a national measurement institute using the method embodied in IEC 60318-1. Having accounted for the actual device dimensions, the thermo-viscous effects inside narrow slots and holes and environmental conditions, the results of the numerical modelling were found to be in good agreement with the measured values.

Practical considerations in the verification of personal sound exposure meters

This paper analyses the problems that appear when calibration or verification of personal sound exposure meters is done following the recommendations of IEC 61252. The tests recommended in the standard to verify the characteristics of such instruments are discussed and alternative procedures are proposed to solve the problems detected. The two main problems detected are related to the duration of the process, which has a direct effect on the verification cost, and the measurement uncertainty. The use of procedures based on measurement modes that are not dependent on integration times, such as when measuring sound pressure level, is recommended whenever possible.

Integration and Validation of a Disruption Predictor Simulator in JET

Abstract Disruptions in tokamak devices are inevitable and can severely damage a tokamak device’s wall. For this reason, different protection mechanisms have to be implemented. In the Joint European Torus (JET), these protection systems are structured in different levels. At the lowest level are those systems that are responsible for protecting the machine’s integrity, which must be highly reliable. More complex systems are located at higher levels; these higher-level systems have been designed to take action before low-level systems. Since the installation of the new metallic wall in JET, new protection systems have been being developed to improve the overall protection of the device. This work focuses on a software application – a disruption predictor – that detects an incoming disruption. This software application simulates the behavior of a real-time implementation. In recent years, efforts have been devoted to developing and optimizing a reliable system that is capable of predicting disruptions. This has been accomplished by the novel combination of machine-learning techniques based on supervised learning methods. Disruptions must be predicted early enough so that the protection systems can mitigate the effects of disruptions. This paper summarizes the software development of the JET disruption predictor. This software simulates the real-time data acquisition and data processing. It has been an essential software tool to both optimize the disruption prediction model and implement a simulator of the real-time predictor.

Microprocessors training in a electrical and electronic degree

The implementation of the curriculum within the EEES in EUIT of Telecommunications of the UPM has enabled a structure to implement the teachings of microprocessors based on the cooperative work. This methodology is based on the development of projects with increasing complexity. This paper details the methods used in each course and resources used. While the academic results obtained to date can not be considered significant because it has not yet been implemented throughout the curriculum, the academic performance of students who have completed these courses have been very favorable.

Design of an advanced intelligent instrument with waveform recognition based on the ITMS platform

Searching for similar behaviours in previous data plays a key role in fusion research, but it can be quite challenging to implement from a practical point of view. This paper describes the design of an intelligent measurement instrument that uses Similar Waveform Recognition Systems (SWRS) to extract knowledge from the signals it acquires. The system is perceived as an ethernet measurement instrument that permits acquisition of several waveforms simultaneously and identification of similar behaviours by searching in previous data using distributed SWRS. The implementation is another example of the advantages that local processing capabilities can provide in Data Acquisition (DAQ) applications.

A low‐cost sound level meter based on personal computer

In this abstract a low‐cost sound level meter is developed with the help of digital signal processing techniques and an integrated programming environment. The instrument is based on the use of a general purpose data acquisition PC card to acquire the signal and a powerful digital signal processing algorithm based on digital filters to compute a one‐third octave band analysis conforming to ANSI S1.11‐1986 in real time. The objective is made possible thanks to the use of optimized signal processing routines from Intel Signal Processing Library. The use of this library and an instrumentation specific integrated programming environment such as LabWindows/CVI (National Instruments) makes it possible to design a low‐cost instrument in a very short time. The algorithm is a multirate filter bank implementation of the standard. The discussion is completed with several simulations and benchmarks are presented for different design situations. Execution time is also compared to that obtained with a popular digital s...