A Demonstration of an Intelligent Control System for a Reusable Rocket Engine

• Main Authors: Musgrave, Jeffrey L, Paxson, Daniel E, Litt, Jonathan S, Merrill, Walter C
• Format: Report
• Language: English
• Subjects: ACTUATION; ALGORITHMS; AUTOMATION; CONTROL SYSTEMS; DEMONSTRATIONS; FAILURE; FAULT TOLERANCE; FLIGHT; INTELLIGENT CONTROL SYSTEMS; INTERFACES; Liquid Propellant Rocket Engines; LOOPS; MAINTENANCE; MISSIONS; MIXTURES; MONITORING; MONITORS; OPERATION; PROPULSION SYSTEMS; RATIOS; REQUIREMENTS; ROCKET PROPULSION; SIMULATION; SPACE SHUTTLES; STRATEGY; THRUST

An Intelligent Control System for reusable rocket engines is under development at NASA Lewis Research Center. The primary objective is to extend the useful life of a reusable rocket propulsion system while minimizing between flight maintenance and maximizing engine life and performance through improved control and monitoring algorithms and additional sensing and actuation. This paper describes current progress towards proof-of-concept of an Intelligent Control System for the Space Shuttle Main Engine. A subset of identifiable and accommodatable engine failure modes is selected for preliminary demonstration. Failure models are developed retaining only first order effects and included in a simplified nonlinear simulation of the rocket engine for analysis under closed loop control. The engine level coordinator acts as an interface between the diagnostic and control systems, and translates thrust and mixture ratio commands dictated by mission requirements, and engine status (health) into engine operational strategies carried out by a multivariable control. Control reconfiguration achieves fault tolerance if the nominal (healthy engine) control cannot. Each of the aforementional functionabilities is discussed in the context of an example to illustrate the operation of the system in the context of a representative failure. A graphical user interface allows the researcher to monitor the Intelligent Control System and engine performance under various failure modes selected for demonstration.