1,682 research outputs found
Simulation and experimental evaluation of a flexible time triggered ethernet architecture applied in satellite nano/micro launchers
The success of small satellites has led to the study of new technologies for the realization of Nano and Micro Launch Vehicle (NMLV) in order to make competitive launch costs. The paper has the objective to define and experimentally investigate the performance of a communication system for NMLV interconnecting the End Systems as On-Board Computer (OBC), telemetry apparatus, Navigation Unit...we propose a low cost Ethernet-based solution able to provide the devices with high interconnection bandwidth. To guarantee hard delays to the Guide, Navigation and Control applications we propose some architectural changes of the traditional Ethernet network with the introduction of a layer implemented in the End Systems and allow for the lack of any contention on the network links. We show how the proposed solution has comparable performance to the one of TTEthernet standard that is a very expensive solution. An experimental test-bed equipped with Ethernet switches and Hercules boards by Texas Instruments is also provided to prove the feasibility of the proposed solution
Enhancing HPC on Virtual Systems in Clouds through Optimizing Virtual Overlay Networks
Virtual Ethernet overlay provides a powerful model for realizing virtual distributed and parallel computing systems with strong isolation, portability, and recoverability properties. However, in extremely high throughput and low latency networks, such overlays can suffer from bandwidth and latency limitations, which is of particular concern in HPC environments. Through a careful and quantitative analysis, I iden- tify three core issues limiting performance: delayed and excessive virtual interrupt delivery into guests, copies between host and guest data buffers during encapsulation, and the semantic gap between virtual Ethernet features and underlying physical network features. I propose three novel optimizations in response: optimistic timer- free virtual interrupt injection, zero-copy cut-through data forwarding, and virtual TCP offload. These optimizations improve the latency and bandwidth of the overlay network on 10 Gbps Ethernet and InfiniBand interconnects, resulting in near-native performance for a wide range of microbenchmarks and MPI application benchmarks
PhyNetLab: An IoT-Based Warehouse Testbed
Future warehouses will be made of modular embedded entities with
communication ability and energy aware operation attached to the traditional
materials handling and warehousing objects. This advancement is mainly to
fulfill the flexibility and scalability needs of the emerging warehouses.
However, it leads to a new layer of complexity during development and
evaluation of such systems due to the multidisciplinarity in logistics,
embedded systems, and wireless communications. Although each discipline
provides theoretical approaches and simulations for these tasks, many issues
are often discovered in a real deployment of the full system. In this paper we
introduce PhyNetLab as a real scale warehouse testbed made of cyber physical
objects (PhyNodes) developed for this type of application. The presented
platform provides a possibility to check the industrial requirement of an
IoT-based warehouse in addition to the typical wireless sensor networks tests.
We describe the hardware and software components of the nodes in addition to
the overall structure of the testbed. Finally, we will demonstrate the
advantages of the testbed by evaluating the performance of the ETSI compliant
radio channel access procedure for an IoT warehouse
Heterogeneous models and analyses in the design of real-time embedded systems - an avionic case-study
The development of embedded systems according to Model-Driven Development relies on two complementary activities: system mod- eling on the one hand and analysis of the non-functional properties, such as timing properties, on the other hand. Yet, the coupling be- tween models and analyses remains largely disregarded so far: e.g. how to apply an analysis on a model? How to manage the analysis process? This paper presents an application of our research on this topic. In particular, we show that our approach makes it possible to combine heterogeneous models and analyses in the design of an avionic system. We use two languages to model the system at di erent levels of abstraction: the industry standard AADL (Ar- chitecture Analysis and Design Language) and the more recent implementation-oriented CPAL language (Cyber-Physical Action Language). We then combine di erent real-time scheduling analy- ses so as to gradually de ne the task and network parameters and nally validate the schedulability of all activities of the system
Multi-Dimensional Model Based Engineering for Performance Critical Computer Systems Using the AADL
International audienceThe Architecture Analysis & Design Language, (AADL), Society of Automotive Engineers (SAE), AS5506, was developed to support quantitative analysis of the runtime architecture of the embedded software system in computer systems with multiple critical operational properties, such as responsiveness, safety-criticality, security, and reliability by allowing a model of the system to be annotated with information relevant to each of these quality concerns and AADL to be extended with analysis-specific properties. It supports modelling of the embedded software runtime architecture, the computer system hardware, and the interface to the physical environment of embedded computer systems and system of systems. It was designed to support a full Model Based Engineering lifecycle including system specification, analysis, system tuning, integration, and upgrade by supporting modelling and analysis at multiple levels of fidelity. A system can be automatically integrated from AADL models when fully specified and when source code is provided for the software components
Embedded control system for an autonomous mobile robot
Diplomová práce se zabývá návrhem a realizací vestavěného řídicího systému určeného pro autonomní mobilní robot Advee. Řídicí systém tvoří vrstvu abstrakce mezi hardwarovými prostředky robotu a vyššími vrstvami řízení, které provádějí lokalizaci robotu a plánování pohybu. V rámci návrhu byla vyvinuta modulární struktura systému a zvoleny prostředky mezimodulové komunikace. Navržený systém byl pak implementován včetně podpory komunikačních standardů EIA-485 a CAN bus. Zvolená architektura systému se v praxi osvědčila --- prototyp robotu Advee řízený popsaným systémem má za sebou více než 500 hodin komerčního provozu s minimem poruch.The master's thesis deals with the design and realization of an embedded control system for the autonomous mobile robot Advee. The control system forms an abstraction layer between the hardware means of the robot and higher control layers that handle robot localization and autonomous navigation. Modular system structure has been designed and inter-process communication mechanism has been chosen. The designed control system has been then implemented with the support for EIA-485 and CAN bus communication standards. The architecture of the system has been verified during more than 500 hours of commercial operation of the robot prototype equipped with the control system.
GCC-Plugin for Automated Accelerator Generation and Integration on Hybrid FPGA-SoCs
In recent years, architectures combining a reconfigurable fabric and a
general purpose processor on a single chip became increasingly popular. Such
hybrid architectures allow extending embedded software with application
specific hardware accelerators to improve performance and/or energy efficiency.
Aiding system designers and programmers at handling the complexity of the
required process of hardware/software (HW/SW) partitioning is an important
issue. Current methods are often restricted, either to bare-metal systems, to
subsets of mainstream programming languages, or require special coding
guidelines, e.g., via annotations. These restrictions still represent a high
entry barrier for the wider community of programmers that new hybrid
architectures are intended for. In this paper we revisit HW/SW partitioning and
present a seamless programming flow for unrestricted, legacy C code. It
consists of a retargetable GCC plugin that automatically identifies code
sections for hardware acceleration and generates code accordingly. The proposed
workflow was evaluated on the Xilinx Zynq platform using unmodified code from
an embedded benchmark suite.Comment: Presented at Second International Workshop on FPGAs for Software
Programmers (FSP 2015) (arXiv:1508.06320
Pando: Personal Volunteer Computing in Browsers
The large penetration and continued growth in ownership of personal
electronic devices represents a freely available and largely untapped source of
computing power. To leverage those, we present Pando, a new volunteer computing
tool based on a declarative concurrent programming model and implemented using
JavaScript, WebRTC, and WebSockets. This tool enables a dynamically varying
number of failure-prone personal devices contributed by volunteers to
parallelize the application of a function on a stream of values, by using the
devices' browsers. We show that Pando can provide throughput improvements
compared to a single personal device, on a variety of compute-bound
applications including animation rendering and image processing. We also show
the flexibility of our approach by deploying Pando on personal devices
connected over a local network, on Grid5000, a French-wide computing grid in a
virtual private network, and seven PlanetLab nodes distributed in a wide area
network over Europe.Comment: 14 pages, 12 figures, 2 table
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