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Journal Article

Skills Synergy Leading to RTM Flow Simulation Success Story

2011-10-18
2011-01-2629
Industrial requirements imply optimizing the development cycle, reducing manufacturing costs and reaching marketable product maturity as fast as possible. The design stage often involves multiple sites and various partners. In this context, the use of computer simulation becomes absolutely necessary to meet industrial needs. Nevertheless, this activity can be effective only if it is integrated correctly in the industrial organization. In the aeronautical and space systems industry, mechanical specifications often require the use of composites reinforced by continuous carbon fibers. The goal of this article is to describe how, on a time frame of nearly twenty years, a series of scientific and technical tasks were carried out in partnership in order to develop, validate and implement Resin Transfer Molding (RTM) flow simulation and cure analysis for high performance composites. The research stage started at the university in 1991.
Technical Paper

Optimal Scheduling and Delay Analysis for AFDX End-Systems

2011-10-18
2011-01-2751
The present work aims at the reduction of transmission delay at the level of AFDX ES (Avionics Full Duplex Switched Ethernet End-Systems). To this end, two approaches, namely Network Calculus and response time analysis (RTA), are employed in the computation of upper bound delay. To evaluate the delay regarding different scheduling policies, the arrival curve of the flow on output of ES is established for given traffic shaping algorithm and service mode. Computational analysis shows that Bandwidth Allocation Gap (BAG) based scheduling is the optimal policy at the level of AFDX ES, which leads to the tightest output arrival curve among all possible scheduling policies. BAG-based scheduling consists in assigning higher priority to virtual links with smaller BAG thus corresponding to the well known Rate-Monotonic Algorithm. Furthermore, schedulability criterion are established based on RTA.
Technical Paper

Model-Based Design Flow Driven by Integrated Modular Avionic Simulations

2013-09-17
2013-01-2211
The Integrated Modular Avionics (IMA) architecture has been a crucial concern for the aerospace industry in developing more complex systems, while seeking to reduce space, weight and power (SWaP), as well as development, certification and production time. From a software perspective, that objective pushes developers to migrate toward safety critical space and time partitioning environment. However, mainstream commercial real-time operating systems (RTOS) offering such partitioning can be restrictive in early development due to very high licensing costs. That situation is even more striking when considering that low-cost alternatives could instead be used for system modeling and early simulation before acquisition of a target platform. This paper reviews existing low-cost and open-source development environments to propose a novel design flow. The proposed methodology starts with model-based analysis in the AADL modeling language.
Journal Article

An AFDX Switch Fabric Hardware Core for Avionic Network Prototyping and Characterization

2012-10-22
2012-01-2123
Avionic Full-Duplex Switched Ethernet (AFDX) is one of the most promising solutions developed in recent years for implementing high-bandwidth Avionic Data Networks (ADNs) that can support the increasingly high information flow required by modern avionic systems. Although AFDX commercial products are available, developing custom implementations using generic software and hardware, without depending on third-party products, allows identifying practical challenges and constraints, prototyping and characterizing new architectures, testing new algorithms, as well as performing validation and verification in the early stage of development. In this paper, we show how an AFDX switch fabric hardware core can be designed and implemented on an FPGA to facilitate the prototyping of a generic ADN in an early development stage.
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