On a Grand Scale
The main purpose of the A350 XWB Cabin 0 Testing Factory is the testing and integration of cabin-related aircraft systems, with a focus on the electrical functions and configuration.
Huge aircraft development programs like the A350XWB bear many risks in the development cycle for aircraft and systems. The risks are intensified by the steadily increasing number of electronic components and growing complexity. To overcome these risks, a lot of test and verification measures are executed during the entire implementation and integration process. Many of the measures are executed with test systems of different size and focus. It is also a fact that the test means become bigger in size and complexity parallel to the systems under test. At the top of aircraft system integration and verification, large-scale testing facilities are necessary.
The A350XWB Cabin0 testing factory illustrates TechSAT’s ability to provide such huge test means. Airbus Deutschland (Airbus) is responsible for the development, integration and test of the complete set of cabin systems for the new Airbus A350XWB aircraft. The modern aircraft cabin is one of the biggest and most complex of the aircraft domains. To mitigate risks during development and integration, Airbus decided to build a complete A350XWB Cabin0 function integration facility.
Following strict screening, Airbus selected the consortium of TechSAT, FTI Engineering Network and EADS RST to deliver the function integration benches (FIB) and integrate all test systems, simulations and configuration tools into a fully-functional testing factory.
Active Development Partnership
One major reason for the selection of the TechSAT consortium was their decades of experience in the development of test systems and simulations. A number of test systems employing TechSAT’s ADS2 middleware had already been successfully used in the A380 development.
This well-proven middleware was selected as the basic test system technology, with a view to improving it for use with future technology. Another advantage was that the consortium could provide employees with extensive knowledge of the test and integration environment on site. One of the main challenges was the just-intime delivery of the test systems parallel to the delivery of the aircraft systems. This was met by the on-site team, and through the continuous integration of test systems in the run-up to the completion of the testing factory. Even the initial integration of aircraft systems into the test systems was achieved by an integrated team supported by the consortium in an active development partnership.
The main purpose of the A350XWB Cabin0 testing factory is the testing and integration of cabin-related aircraft systems, with a focus on the electrical functions and configuration. The testing factory is used for initial integration and verification during the aircraft development phase, and subsequently for verification of cabin configuration variants according to the airline demands. The testing factory consists of 14 function integration benches (FIB).
The test systems installed in the testing factory cover the following ATA chapters: ATA21 air conditioning, ATA23 communications, ATA24 electrical power, ATA26 fire protection, ATA29 hydraulic power, ATA30 ice protection, and ATA31 indication and recording system. ATA33 lights, ATA35 oxygen, ATA36 pneumatic, ATA42 integrated modular avionics, ATA44 cabin systems, ATA45 diagnostic and maintenance system, ATA46 information system, and ATA52 doors are also installed there All test means are used either in standalone mode or as a cluster of test systems and in connection with the Cabin0 V&V platform.
Numerous top-level requirements that were at first glance contradictory had to be solved using appropriate technological concepts. To keep costs down it was necessary to use inexpensive COTS components wherever possible, for example an industrial PC instead of VME products. However, the short development cycles in PC technology have a negative impact on the long-term availability of components. The lifetime of even industrial PC components does not meet the usual life cycle of aerospace test systems.
A scalable distributed computing and I/O architecture had to be provided because of the spatial distribution of the testing factory and its division into individually usable functional test benches. On the other hand, large numbers of process variables need to be processed in short cycle times. Another challenge was posed by the requirement of a comprehensive SIM/REAL concept. This would allow the integration of selected components of the aircraft systems, either as real original equipment or simulation, without changing parts of the test system.
NGTS Technology Platform
Based on these requirements, TechSAT has designed the new generation test system (NGTS) platform. This platform is essentially based on the Avionics Development System 2nd Generation (ADS2) that was well known at Airbus and also proven over many years in the A380 program.
A third release of the ADS2 middleware was carried out, to support all of the required features of the NGTS platform. Major improvements include the support of distributed real-time PC-based computing and high efficient data exchange mechanisms (for example, ADS2/DXP). The new future architecture system technology (FAST) I/O family was also developed, to complete TechSAT’s concept of functional modules.
Based on the underlying ADS2 cluster concept and the use of standard Ethernet hardware, FAST allows the designing of highly scalable and flexible test systems. The concept of functional modules makes it possible that test systems remain form-, fit- and function-compatible with ongoing technological development. With this approach, single test systems as well as testing factories can be kept operational for decades.
The new FAST I/O family consists of configurable avionics interfaces with integrated standard signal conditioning capabilities and switching between simulated and real aircraft equipment.
The required SIM/REAL concept could not be reasonably implemented with COTS components, as the expected number of I/O channels was too big. Even in the testing factory, sufficient space was not available for the related wiring and switching matrices. The FAST DSIO24, for example, is a compact discrete I/O interface board featuring 24 individually configurable input or output channels with pull up/down capability, permanent monitoring, manual breakout, two independent switched UUT interconnections, and complete switching between simulation and original equipment (OE). The interface to the UUT and the OE is realized by separate DSUB25 connectors and a standard RJ45 Ethernet interface for connection to the I/O network. This allows smart test system design and easy maintenance over the entire life cycle.
The avionics bus interfaces – AFDX, ARINC 429 and CAN – were realized using the existing TechSAT PMC solutions on PCI or cPCI carrier. For ARINC 429 and CAN busses, the SIM/ REAL concept was realized by separate bus box devices.
To implement the SIM/REAL concept for the aircraft system AFDX connections as well, a special lab AFDX switch, the enhanced real AFDX switch (ERAS), was integrated into the ADS2 technology platform.
The generic simulation framework ADS2 GSF was enhanced to allow seamless integration of simulations created with third-party tools, such as MATLAB/Simulink, LabVIEW, or common C/C++ IDE. This allows testers to reuse many existing simulations from earlier projects.
To reduce user training, the handling of the test session has remained nearly unchanged, compared with the known A380 ADS2 test environment. A cluster of test systems can be used in the same way as a single functional integration bench. Comprehensive simulation features allowed early A/C system integration even when the original equipment was not yet available.
In the A350XWB Cabin0 Testing Factory, complex test scenarios with up to 1.2 million process variables in cycle times of around 50 ms can be executed on the ADS2 test system cluster.
In the meantime, TechSAT has developed many additional NGTS components to fulfill the testing requirements of both small test systems and big test facilities. The next release of the ADS2 software is currently under development, to incorporate the experiences of the A350XWB projects and to further improve performance and usability.
With new tools and methods (test suites, ICD tools, modelling tool integration, and so on), everything is combined into a seamless ADS2-based technology platform.
The testers’ operating experience is permanently incorporated in the improvement of TechSAT ADS2 and its components. In the meantime, the value of the ADS2 NGTS technology platform has been successfully proven in several other test system projects.
The latest evolution of the TechSAT technology platform is the transfer of NGTS concepts and technology to both small test systems, such as MAYA, and integrated solutions supporting classic and model-based development.
Because of this experience, TechSAT is now able to realize integration and test means supporting all activities, from the beginning to the end of an avionics development project.
Ultimately, the size of test means is a direct consequence of the integration and verification requirements for the aircraft system. Nevertheless, it’s important to rely on a smart technology platform that is scalable and flexible to meet all the integration and verification requirements over the entire product life cycle.
A test facility composed of function integration benches allows verification of defined sub-systems as well as entire aircraft systems. Complementary simulations, configuration and test tools make such a testing factory extremely efficient.