• Video
  • 21-Mar-2012 10:00 EDT

Optimal Scheduling and Delay Analysis for AFDX End-Systems

00:24:45
Length:

Purchase Required to View Video

Short Preview Below

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. Additionally, delay bound computation indicates that response time analysis provides a tighter delay bound than that obtained by Network Calculus. Numerical simulations are carried out to confirm the validity, the applicability, and the performance of the proposed scheduling scheme.

Presenter
Guchuan Zhu

Buy
Select
Price
List
Purchase to View
$19.00
Learn More
11VATC40302
Optimal Scheduling and Delay Analysis for AFDX End-Systems
2011-10-20
OPTIMAL SCHEDULING AND DELAY A
Share
HTML for Linking to Page
Page URL
Grade
Rate It
No ratings yet

View More Video

Video
2012-03-19
By introducing the concept of a separation between graphics and logic, interpreted run time architecture, and defined communication protocol, the ARINC 661 standard has addressed many of the concerns that aircraft manufacturers face when creating cockpit avionics displays. However, before kicking off a project based on the standard, it is important to understand all aspects of the standard, as well as the benefits and occasional drawbacks of developing with ARINC 661 in mind. This white paper will first provide an overview of ARINC 661 to clarify its concepts and how these relate to the development process. The paper will also describe the benefits of using a distributed development approach, and will outline practical, real world considerations for implementing an ARINC 661-based solution. Finally, readers will learn how commercial tools can be used to simplify the creation of displays following the standard to speed development and reduce costs.
Video
2012-03-21
As a result of recommendation from the Augustine Panel, the direction for Human Space Flight has been altered from the original plan referred to as Constellation. NASA's Human Exploration Framework Team (HEFT) proposes the use of a Shuttle Derived Heavy Lift Launch Vehicle (SDLV) and an Orion derived spacecraft (salvaged from Constellation) to support a new flexible direction for space exploration. The SDLV must be developed within an environment of a constrained budget and a preferred fast development schedule. Thus, it has been proposed to utilize existing assets from the Shuttle Program to speed development at a lower cost. These existing assets should not only include structures such as external tanks or solid rockets, but also the Flight Software which has traditionally been a ?long pole? in new development efforts. The avionics and software for the Space Shuttle was primarily developed in the 70's and considered state of the art for that time.
Video
2012-03-21
Design and Development of a Terabyte of Data Storage for Spaceflight. Presenter Chris Thames, NASA
Video
2012-03-21
The System Architecture Virtual Integration (SAVI) program is a collaboration of industry, government, and academic organizations within the Aerospace Vehicle System Institute (AVSI) with the goal of structuring a new integration process that relies on a single-truth architectural framework. The SAVI approach of Integrate, then Build provides a modern distributed development environment which arrests the propagation of requirements errors through the development life cycle. It does so by capturing design assumptions and shared properties of the system design in an authoritative, annotated architectural model. This reference model provides a common, analyzable framework for confirming that system requirements remain complete, consistent, and correct at all levels of system decomposition. Core concepts of SAVI include extensive use of model-based system engineering tools and use of a single-truth reference architectural model.

Related Items

Technical Paper / Journal Article
2011-04-12
Technical Paper / Journal Article
2013-04-08
Standard
2014-04-16