The Controls and Dynamics Branch is committed to working cooperatively with its space and aeronautics customers to research, develop and demonstrate technologies for advanced control concepts and dynamic modeling that enhance performance, safety, environmental compatibility, reliability and durability of aerospace propulsion systems.
The controls technology areas include fault diagnostics, health management, active combustion control, active stall control, turbomachinery system stability management, intelligent engine control, inlet control, integrated flight/propulsion control, nonlinear and robust multivariable control synthesis techniques, and life extending control. The dynamic modeling work includes modeling of advanced turbomachinery concepts and components, and cross-disciplinary research between controls and computational fluid dynamics (CFD).
Overview of Propulsion Controls and Diagnostics Research
An overview paper describing our current propulsion controls and diagnostics research in support of NASA Aeronautics and Exploration Mission programs is available:
Dr. Sanjay Garg Elected to AIAA Board of Directors
Dr. Sanjay Garg was elected to the position of AIAA Director – Technical, Information Systems Group (ISG) in the recent AIAA Board of Director elections. The ISG consists of the following Technical Committees (TCs): Communications Systems, Computer Systems, Digital Avionics, Information and Command & Control Systems, Intelligent Systems, Sensor Systems, and Software. Dr. Garg will have the following responsibilities – participate in the Technical Activities Committee (TAC) which provides overall direction of AIAA technical activities such as conferences, technical excellence awards etc.; provide overall guidance to the TCs in the ASG to make sure TC activities are aligned with AIAA strategic goals; and participate in the AIAA Board of Directors meeting to set the overall direction for AIAA.
NASA Tech Brief on Sensor Data Qualification Published
An article describing technology disclosure LEW-18633-1, "Onboard Sensor Data Qualification in Human-Rated Launch Vehicles" has been published in the October 2012 edition of NASA Tech Briefs. Sensor Data Qualification (SDQ) is a set of algorithms that can be implemented in onboard flight software, and can be used to qualify data obtained from flight-critical sensors prior to the data being used by other flight software algorithms. Qualified data has been analyzed by SDQ and is determined to be a true representation of the sensed system state; that is, the sensor data is determined not to be corrupted by sensor faults or signal transmission faults. The reported SDQ technology was developed by Kevin Melcher and Edmond Wong from RHC; William Maul, Amy Chicatelli, Shane Sowers, and Christopher Fulton, formerly of QinetiQ North America and now with Vantage LLC; and Randall Bickford of Expert Microsystems Inc.
Intelligent Systems Book Chapter Co-authored by Kevin Melcher
The book, "Advances in Intelligent and Autonomous Aerospace Systems," was recently published by AIAA (American Association of Aeronautics and Astronautics) as part of their Progress in Astronautics and Aeronautics book series. The book includes a chapter "Integrated Systems Health Management for Intelligent Systems" which is co-authored by Fernando Figueroa (Stennis Space Center), and Kevin Melcher (GRC). This chapter presents Integrated Systems Health Management (ISHM) as an enabling discipline/technology area for intelligent systems and as a capability that embodies "intelligence" in itself. To that end, a variety of intelligent systems-relevant ISHM topics and examples are presented. The chapter provides the reader with an understanding of the state-of-the-art, current research, and challenges that are relevant to ISHM as a core capability of an intelligent system.
Chapter on Intelligent Propulsion Control Published in AIAA Book on Advances in Intelligent and Autonomous Aerospace Systems
The book "Advances in Intelligent and Autonomous Aerospace Systems" was recently published by AIAA (American Association of Aeronautics and Astronautics) as part of their Progress in Astronautics and Aeronautics book series. The book includes a chapter "Intelligent Propulsion Control and Health Management" authored by Dr. Sanjay Garg. This chapter focuses on description of the control logic that is incorporated into the FADEC (Full Authority Digital Engine Control) to provide safe and reliable operation of the engine throughout the operating envelope while also guaranteeing a certain operating life of the engine. The chapter starts with a basic introduction to high-bypass turbofan engine operation and dynamic modeling, and then provides an overview of the state-of-the-art of engine control, some retrofit engine control concepts for increased life and reliability, and the future concept of engine control and diagnostics based on an on-board engine model.
Patent Issued for Thrust Estimation Scheme
United States Patent No. 8,185,292 B2, "Method for Estimation of at Least One Engine Parameter," was issued to Jonathan Litt on May 22, 2012. It covers an approach to detect engine component faults and estimate unmeasurable engine outputs in flight accounting for the effect of engine deterioration. The approach minimizes deterioration-related modeling uncertainty by capturing the effect of engine deterioration in a reduced order model in such a way that variables that can be estimated are used to reconstruct the selected unmeasurable outputs.
NESC Webcast on Fundamentals of Aircraft Engine Control
Dr. Sanjay Garg presented a webcast on “Fundamentals of Aircraft Engine Control” on Nov. 16, 2011, as part of the webcast series being organized by the NESC (NASA Engineering and Safety Center) GNC (Guidance, Navigation and Control) technology discipline team. This was the first presentation of the hour long webcasts which are scheduled to be held every other month and are open to NASA civil servants and on-site contractors. The webcasts are being organized through the NESC Academy. The recorded webcast is available for viewing through the NESC Academy website – click on link below. This video provides a good opportunity for both propulsion engineers and controls engineers to have a basic understanding of the control law design challenges associated with providing safe and reliable operation of commercial aircraft turbofan engines while meeting the performance requirements and also guaranteeing a certain operating life of the engine. This video is excellent for showing to students in the senior level propulsion class under the typical undergraduate aerospace curriculum to give them exposure to dynamics and control issues associated with turbofan engines.
Tutorial on Aircraft Engine Control and Gas Path Health Management Presented at 2012 Turbo Expo
Dr. Sanjay Garg and Mr. Donald Simon presented a two hour tutorial on “Challenges in Aircraft Engine Control and Gas Path Health Management” at the 2012 IGTI (International Gas Turbine Institute) Turbo Expo conference, held June 11-15 in Copenhagen, Denmark. The tutorial session presented the state-of-the-art of control and gas path diagnostics as implemented on modern commercial turbofan engines, and followed up with emerging approaches for controls and gas path health management technology development to address the challenging requirements of increased propulsion system efficiency, safety and reliability, and reduced environmental impact and life time operation costs. The tutorial was attended by over 50 conference participants, and for many of them this was their first exposure to the controls and diagnostics technology issues for aircraft engines. The audience interest was evident from the extensive discussion at the end of the presentation. The presentation was made on June 12, and throughout the rest of the conference, the session attendees complimented Don and Sanjay on helping them understand the relevance of controls and diagnostics technologies to improved performance and safe operation of aircraft engines. Over 35 attendees requested copies of the presentation charts.
Communications, Instrumentation & Controls Division
NASA Glenn Research Center
responsible official: sanjay garg
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last updated: 10.19.12