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Braking Systems with New IMA Generation
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 18, 2011 by SAE International in United States
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First generation of Integrated Modular Avionics (IMA), currently onboard in aircraft type Airbus A380, A400M, or designed for Airbus A350, and whose principle was initially to introduce some common processing resources, had been developed in such a way to reduce the quantity of embedded equipment part number, and to harmonize the nature of the avionic units by minimizing the specificity of electronic equipment: thus, for instance, the number of processing units in the A380 is half that of previous LRU-based avionic generations.
This type of architecture had already much interest at aircraft level; nevertheless, some of the designed electronic components were not able to support some performance requirements of the function suppliers, such as Messier-Bugatti-Dowty, which had to limit the deployment of the functions to implement in IMA; For this reason, it was still necessary to execute the fast control loops, as the antiskid algorithms, in specific remote electronics (RDC, RBCU), independently from the standardized CPIOM.
Beyond this first generation of avionics architecture, new more optimised concepts are presently studied, through research programs as SCARLETT (IMA of second generation, “IMA2G”), where Messier-Bugatti-Dowty takes part to the definition and the evaluation of new modular electronics standard, more powerful and capable to host the most critical and fast control functions, and in such a way to ensure that the performance of these defined generic components (middleware, reduced API653 layer), plus the latency introduced by the fast field bus match well with the high time critical performances required, for example, for the execution of the braking regulation. In particular, the antiskid function needs very low latency and jitter, and full deterministic transmission to operate nominally.
Furthermore, actual research study on braking, landing gear and aircraft on ground control laws requires more and more real-time power and fast control loops to provide new functionalities and higher efficiency, and necessary to be considered in the design of these new platforms.
The target is, thus, to reach more standardized and scalable avionics, dedicated to the highest critical aircraft functions as the braking control, and standard capable to facilitate the high critical system integration and to harmonize the development and test process, regarding the final common objective (at aircraft and system levels) to reduce the development time and cost, without compromising the trend of more efficient and powerful real time control laws with adaptive behaviour.