Perspective for Distributed Intelligent Engine Controls of the Future

Over the past fifty years, we have witnessed advances in the fields of communication, computation, and control. As these fields have converged, they have provided strength and new capabilities for the design of turbine engine controls of the future. Digital Engine Controls were introduced in the 1970s with the DEEC for the PW JT9D. The transition to Full Authority Digital Engine Controls (FADEC) in the 1980s was a natural response to the demand for more capabilities for the engine and was made possible by the increasing capabilities of electronics. In recent years the combination of extreme criticality and severe environments has naturally slowed down the insertion of electronics and other technologies into the FADEC world. The current generations of FADECs are highly customized, centralized systems that require significant development cost and are expensive to maintain. Distributed architecture FADEC systems have the potential for eliminating these limitations and can be scaled to meet the needs of future generations of propulsion systems.

The perspective on the future of distributed engine controls in terms of the implementation and analysis of what we envision could be the next phase of the turbine engine controls technology revolution using high temperature electronics. In a distributed environment, intelligent control system platforms can play the role of key differentiator in terms of system and software architecture development approach, safety, performance, system integration, engine maintenance, obsolescence management, upgradeability, system reuse and other lifecycle costs. Turbine engines of the future are more complex and require smart sensors, smart actuators, constant monitoring and require capability for rapidly processing many parameters. Future engines must also run hotter and will require more electronics in the harsh engine environments. We begin by first examining the limitations and challenges of today's FADEC systems and making the case for the development of high temperature capable electronics as an essential ingredient for implementing distributed FADEC control systems. The industry and the government have been closely working together towards this goal by providing the resource necessary for realization of a more affordable, intelligent and reliable real-time and fault tolerance distributed engine controls for the next generation of aircrafts and engines. As a part of this effort, a Government and industry working group, named DECWG (Digital Engine Control Working Group) has been established. The architecture and building blocks of the distributed FADEC system as envisioned by this group. The Government's sponsorship of R&D activities in support of the high temperature electronics initiative is described. The analysis of the applicability of the distributed architecture in terms of the controls and communication issues and examination of the potential benefits and challenges for implementing distributed FADEC systems. The potential benefits of using high temperature electronics for reducing the fuel cooling requirements and simplifying the thermal management systems should be examined.