Digital Electronic Engine Control Fault Detection and Accommodation Flight Evaluation
Baer-Riedhart, Jennifer L. (1984) Digital Electronic Engine Control Fault Detection and Accommodation Flight Evaluation.
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Abstract
The National Aeronautics and Space Administration (NASA), the U.S. Air Force (USAF), and the U.S. Navy (USN), along with the other government agencies, are conducting various studies of existing and projected engine control systems to investigate the capabilities and performance of various fault detection and accommodation (FDA) schemes. These studies have made extensive use of analytical methods and simulations. Limited altitude testing has also been accomplished in support of these studies. With the advancement of the full-authority digital engine control systems, there has been an increasing desire to perform in-flight evaluations of FDA methodology for substantiating the predictions and facility results of the studies. Recent flight test of the digital electronic engine control (DEEC) in an F-15 airplane have shown discrepancies between flight results and predictions based on simulation and altitude testing, and thus reinforce the need for flight evaluations. However, the difficulty of inducing realistic faults in flight has so far minimized flight testing of the FDA logic. The DEEC is a full-authority, engine-mounted, fuel-cooled digital electronic control system that performs the functions of the standard F100 engine hydromechanical unified fuel control and the supervisory digital engine electronic control. The DEEC consists of a single-channel digital controller with selevtve input-output redundancy, and a simple hydromechanical backup control. The FDA features of the system are a significant portion of the control program. During the course of the recent flight program, the DEEC detected and accommodated two sensor faults, with no false failure indications. An opportunity exists to conduct further flight evaluations of the DEEC FDA in the near future. The objectives of the program will be to induce selected faults and evaluate the resulting actions of the controller. Comparisons will be made between the flight results and predictions, as part of the evaluation. It is anticipated that the FDA data base will be expanded and techniques developed for safely evaluating FDA methodology in flight that may be useful on future programs. This paper will describe the FDA methodology and logic currently in the DEEC system, and discuss the results of the flight failures that have occurred to date . The proposed flight program and anticipated results will be presented at this time.
| EPrint Type: | Other |
|---|---|
| Keywords: | Digital control, Engine control, Flight tests, F-15 engine, F100. |
| Subjects: | (01 - 09) Aeronautics: (07) Aircraft Propulsion And Power Aircraft/Project: F-15 |
| ID Code: | 2027 |
| Deposited On: | 14 July 2009 |
| Additional Information: | 20 pages. NASA CP-2298, Paper 7, Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane, March, 1984, pp. 107-126. |
