F. R. Palomo

Reconfigurable distributed network control system for industrial plant automation

Use of advanced communication technologies, highly integrated control, and programming platforms drastically increases the performance of industrial control systems. That is the case of Motronic, where the synergistic collaboration between industry and academia has led to an advanced distributed network control system. To be commercially successful, it needs to have a low cost and to be robust, even if this requirement implies that it is a custom design and not based on previously existing commercial solutions. Use of standards and off-the-shelf products lower development costs, but usually raise production costs. In this paper, we show that, in certain applications, design of a new system from scratch is more advantageous. This system comprises a set of dynamically reconfigurable local controller nodes, a graphical programming environment, a remote supervision and control system, and a fault-tolerant fiber optical network. TCP/IP connectivity is provided by the use of a local gateway. Motronic is currently being applied in the integrated control of large production plants and in energy and power management industries.

A Novel Co-Design Approach for Soft Errors Mitigation in Embedded Systems

There is an increasing concern about the mitigation of radiation effects in embedded systems. This fact is demanding new flexible design methodologies and tools that allow dealing with design constraints and dependability requirements at the same time. This paper presents a novel proposal to design radiation-tolerant embedded systems combining hardware and software mitigation techniques. A hardening infrastructure, which facilitates the design space exploration and the trade-offs analyses, has been developed to support this fault tolerance co-design approach. The advantages of our proposal are illustrated by means of a case study.

Pulsed Laser SEU Cross Section Measurement Using Coincidence Detectors

This work presents the determination of a Pulsed Laser SEU Cross-Section (Count Statistics). In this work, a coincidence detector has been used to count fault events by comparing the digital VLSI circuit under test with a replica of the design running on a control FPGA. A SEU is declared when a specific fault pattern is detected. The target chip design generates specific fault patterns under pulsed laser shinning. Sweeping the laser energy on a flip flop of a Shift Register, data for a cross section analysis it is obtained. The coincidence detector was previously tested in a preliminary radiation test, so all the lessons learned in the design of radiation test can be translated for future works. In this work it has been used the pulsed laser facilities of Spanish National Laser Center in Salamanca.

Simulation of Total Ionising Dose in MOS capacitors

Total Ionising Dose (TID) effects are the most important effects of ionising radiation in MOS devices. Among others, TID cause charge trapping in the oxide and in the oxide-semiconductor interface. In this work we develop physical simulation models of charge trapping TID effects in MOS capacitors, in order to have a calculation model for postirradiation experiments. Simulations are made using the Sentaurus TCAD suite, comparing results with well established literature. We calculate the modifications in the C-V curve and the dependence of the flat band voltage due to charge trapping in the oxide, interface traps and the combination of both for increasing dose.

Soft core based embedded systems in critical aerospace applications

There is an increasing interest in the aerospace industry to reduce the cost of the systems by means of using Commercial Off The Shelf (COTS) devices. The engineering of novel microsatellites and nanosatellites are clear examples of this new trend. However, the use of sub-micron technologies has led to greater sensitivity of these devices to radiation-induced transient faults, limiting the exploitation of this approach in critical systems. This paper presents an innovative application of soft-core microprocessor based embedded systems, to design dependable and reduced-cost critical systems with COTS reconfigurable devices (flash based FPGAs). To make this possible, it is necessary to fine-tune the protection strategy by combining selectively fault mitigation techniques based on hardware or software. In this way, the resultant system not only fulfills both the design constraints and the dependability requirements, but also avoids the cost provoked by excessive use of protection mechanisms. A case study is presented in which the design space exploration between hardware and software protection techniques permits to find the best trade-offs among performance, reliability, memory size and hardware cost in a dependable subsystem.

Rapid Prototyping of Radiation-Tolerant Embedded Systems on FPGA

Technological advances of Field Programmable Gate Array (FPGA) are making that this technology becomes the most preferred platform for the rapid prototyping of highly integrated digital systems. In addition, protection of processor-based systems to mitigate the harmful effects of radiation-induced upset events is gaining importance while technology shrinks. In this context, the main contribution of this work is a novel rapid prototyping approach for the co-design of dependable embedded systems using FPGA. This is supported by a hardening platform that allows combining software-only fault-tolerance techniques with hardware-only approaches, representing several trade-offs among design constraints, reliability and cost. As case study, several radiation-tolerant embedded systems have been developed based on a technology-independent version of the Picoblaze processor.

TCAD Simulations on CMOS Propagation Induced Pulse Broadening Effect: Dependence Analysis on the Threshold Voltage

Propagation induced pulse broadening (PIPB) effect is becoming a major concern for electronic designers since new technologies are fast enough to propagate and capture Single Event Transients (SET). In this paper, we explore the influence of the MOSFET threshold voltage (VT) on PIPB effect by TCAD simulating the propagation of an SET after an ion strike, showing up this dependence by the modification of some CMOS technology parameters affecting VT. For this work, the test vehicle used to measure PIPB effect is a self-feedback chain of CMOS inverters. The conclusions outlined can be useful when designing with Multi-Vt nano-metric CMOS technologies. Our results suggest that the |VT|/VDD ratio could be a figure of merit for SET propagation broadening.

Simulation methodology for dose effects in lateral DMOS transistors

Due to the increasing interest on laterally diffused MOS (LDMOS) transistors as a part of power electronics in the high energy physics (HEP) experiments, the effect of total ionising dose (TID) on their electrical performances has been experimentally measured. The analysis of the experimental results requires the aid of physics-based simulations to study the impact of TID effects on the LDMOS drift oxide layer. In this work, a simulation methodology is developed in order to analyse the changes in the electric field distribution as a consequence of the TID induced trapped charge, and its relationship with the technological parameters and the bias conditions. The simulation results are compared with the experimental data.

Influence of the fiber coating on the proton radiation sensitivity of Fiber Bragg Gratings

We report on the effect of the fiber coating on the radiation sensitivity of Fiber Bragg Gratings (FBG). For the first time this type of study has been carried out using a 13.5 MeV proton beam up to a fluence of 3.3 × 1015 protons/cm2 (total absorbed dose of 15 MGy). We observed a clear dependence of the radiation sensitivity on the coating, in particular, we have investigated the irradiation induced changes on the strain sensitivity; FBG strain coefficient remains stable for all the fiber within a 5%. This result demonstrates the suitability of FBGs as displacement transducers in the very hostile environment of the new generation of high-intensity particle physics proton colliders

Detectors and Concepts for sub-100 ps timing with gaseous detectors

We give a short compendium of the main ongoing detectors and concepts capable of performing accurate sub-100 ps timing at high particle fluxes and on large areas, through technologies based on gaseous media. We briefly discuss the state-of-the-art, technological limitations and prospects, and a new bizarre idea.