8/6/2019 Real Time Testin f Eng

1/1

Mlcro-Computer/Parallel Processlng For RealTime Testing Of Gas Turblne Control SystemsS. P. Roth & L. A. CelibertiControls EngineeringEngineering DivisionPratt & WhitneyWest Palm Beach. Florida

AbstractThe role that digital electronics have played incontrolling gas turbine engines has changeddramatically over the last 20 years. They haveevolved from simple turbine temperature limiters in the1960s to the present day redundant, full authority,electronic control systems for highly integrated,Advanced Aircraft with thrust vectoringlreversingcapability. This trend towards increasing complexity.has imposed significant demands and challenges onthe development and verification process of digitalelectronic control hardware and software. To keeppace, more sophisticated support equipment is neededto provide a realistic test environment. This equipmentmust realis tically emulate the electro-mechanicalinterfaces. hydromechanical control components. jetengine process and flight control interfaces, tofacilitate early conceptual design evaluations includingflight control integration and flight testing.Pratt & Whitnev (P&WI has successfullv develooed an4'

Figure 1 illustrates the many areas that interact, andmust be considered, to derive the maximum benefitsfrom con trol integration. Flight and engine simulationsmust have an acceptable ievei of fidelity to properlyexplore the system interactions. The various controlsystems will communicate by digital (optic orelectronic) data links that must be structured to allowtimely and accurate exchange of critical informationwithout overburdening the entire aircraft computersystem. Maintenance and Diagnostics need to befacilitated by the use of common secondary power forelectrical and hydraulic power. This avoids componentduplication and allows total flight control system andpropulsion control system checkout with commonground test equipment. For designers to produce areliable, integrated system design, coordinateddevelopment processes and integrated test supportsystems will be required.SystemArchitecture Redundancy

1 anagementIntegratedLoqic/Modes \IntegratedFlight and Propulsion

Experlmentat .Multi-processor Real .Time 'EngineSimulation System that meets these needs. Thissystem is now being used to verify the Full Authorityengines. The next logical step is establishing facilitiesthat support flight and propulsion control systemintegration and fault tolerance studies. This pap erpresents the evolution, design and use of these Interface Links

MaintenaW-3Digital Electronic Controls (FADEC's) for fufure Flight/EngineSimulations and DiagnoskxCommunicationilot-

Figure 1. Areas of Integrated Control Activitiesicroprocessor based real time simulation benches atP&W and the role thev will olav In the develooment and~ ~. , ~.test of integrated flight and propulsion control systemsfor future advanced aircraft.lntroduct lon

The trends towards increasing control complexity andemphasis on flightlpropulsion system integration. haveimposed slgnlficant challenges on the developmentprocess of both flight and propulsion control hardwareand software. Future weapon systems such asAdvanced Short Take-Off and Vertical Landing(ASTOVL) aircraft wiii require a greater degree ofcoordination between aircraft and engine controldesigners to achieve the necessary levels ofintegration.v

1"Copy r igh t @ 1987 by PEW. Pu bl is he d by t he.Pmer ican I i i s F i tu te o f , ,Ae ronau t ics and As t r onau t ics ,I n c . w i t h p e r mi s s io n .

The development process for such advancedintegrated aircraft flight and propulsion control systemswill be carried out by the airframe and enginedesigners working interactively and in parallel. Thisapproach is needed to ensure that the bestperformance of the complete aircraft system isrealized. The design interactions are important andmust be addressed during the preliminary anafysisthrough development testing and final qualification.Advancements In microprocessor technology andmodeling techniques are providing the control systemdesigners with much greater and more economicalsimulation capabilities to properly support this