AVISTA Software Engineers assisted with the development of all-new control software for a family of new generation Geared Turbo Fan Jet engines designed and built by a world leader in commercial jet engines.
Tightly integrated with this company’s workforce spread over three continents, AVISTA engineers developed software for Engine Ignition Start/Shutdown, Engine Control, Fuel Control, Power/Thrust Settings and Control, Cowl Anti-Ice Monitor and Activation, Air Bleed Flow Control (for anti-ice and starting), Thrust Reverser safe deployment, and Health Management and Cross Engine coordination over multiple Aircraft interfaces (ARINC). This engine made significant strides in jet engine fuel efficiency and reduced noise.
Especially challenging was the separation of requirements, model-based artifacts, and hand-code into elements that were common across all engine and airframe variants versus those that were specific to each engine variant installed on a particular manufacturer’s airframe with its communications and cockpit controls differences.
Using an Agile framework, AVISTA engineers updated and reviewed system, high, and low level software requirements (using DOORS), performed model-based design (MBD) using Simulink/Stateflow, tested those designs using both model (MIL) and software in the loop (SIL) proprietary test environments. Multi-processor control and protection logic was implemented and tested across a dual channel CAN bus fault-tolerant architecture.
Rigorous preliminary and critical design reviews for each user story were signed off with Hardware and Chief Engineers prior to each short-cycle build. Each review required successful SIL test results on the dry-bench where engine and airframe plant models interacted with the FADEC control system. As data was collected from test engine runs (wet-bench) and pre-certification test flights, AVISTA helped analyze defects and propose solutions.
Early in the program’s development, deformation of the rotor shaft due to asymmetrical cooling between successive shutdown/startup caused hardware damage. Mechanical alterations strengthened the shaft bearings. But software design changes were made to more effectively cool the engine on shutdown. The AVISTA team not only implemented the software requirements, design, and tests for the new startup/shutdown procedure, but also ensured that all platform and airframe variants were upgraded and tested with the new design.