NATIONAL INSTITUTE OF AEROSPACE

Luis G. Crespo

Luis G. Crespo

Tel:  +1 (757) 864 8444; Fax: +1 (757) 864 7797

Email: lgcrespo@nianet.org

Research Interests

  • Aeronautical systems,
  • Rigid body mechanics, 
  • Nonlinear dynamics,
  • Optimal an adaptive control,
  • Uncertainty quantification,
  • Reliability analysis and robust design, and
  • Aircraft control.

Education

  • Ph.D. Mechanical Engineering, University of Delaware, Newark, DE, USA
  • M.S. Mechanical Engineering, Universidad de Los Andes, Bogota, Colombia
  • B.S. Mechanical Engineering, Universidad de Los Andes, Bogota, Columbia

Current Research

  • Uncertainty-based methods: the goal of this project is to develop rigorous and efficient techniques for uncertainty quantification and robust design of systems subject to parametric uncertainty where epistemic variables, aleatory variables, and imprecise uncertainty models are present. Applications to aviation safety for upset recovery of remotely operated air vehicles near stall are being considered.
  • Aircraft control: This research effort focuses on the analysis and tuning of flight controllers for safe flight. The controller’s architecture consists of a nominal, non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness to aerodynamic uncertainties and actuator failures under off-nominal ones. Applications to the control of subsonic UAVs and hypersonic aircraft are being considered.
  • Aircraft conceptual design: Research in the area of uncertainty management and stability and control for aircraft conceptual design is carried out. The objectives of this effort are twofold. First, we are developing a probabilistic analysis framework of multi-disciplinary models of aircraft with varying levels of fidelity. This framework not only provides a probabilistic assessment of the satisfaction of the mission requirements, but also allows tuning decision variables according to different robustness- and reliability-based policies. This leads to robust designs, whose refinement will be carried out in subsequent stages of the design cycle, having a greater chance of meeting the system requirements. Second, a toolbox for the assessment of the stability and control characteristics of fixed wing transport aircraft is being developed. The Trim and Static module of the Matlab Stability and Control Toolbox (MASCOT) is now in the public domain. This module performs a low-fidelity stability and control assessment of an aircraft model according to the particular vehicle geometry and inertial properties. This is assessment is carried out by evaluating both the control authority of the actuators, and the static stability characteristics of the aircraft for a set of critical flying conditions. These conditions include horizontal flight, take-off rotation, landing flare, steady roll, steady turn and pull-up/push-over flight.

Recent Publications

 Crespo L. G., Kenny S. P., Giesy D. P.; Reliability analysis of polynomial systems with imprecise probabilities, Mechanical Systems and Signal Processing, 2012.

Crespo L. G., Giesy D. P., Kenny S. P; Bernstein special issue: uncertainty quantification in the presence of aleatory and epistemic uncertainties, Reliable Computing, 2012.

Crespo L. G., Matsutani M., Annaswamy A. M.; Design of a model reference adaptive controller for a remotely operated air-vehicle, AIAA Journal of Guidance, Control and Dynamics, V 35, N 2, p 406-422, 2012.

Liu, Y., Crespo, L. G.; Adaptive control allocation in the presence of actuator failures, Journal of Control Science and Engineering, 2012.

Kenny S. P., Crespo L. G., Giesy D. P.; Dimensionality reduction for uncertain dynamic systems, International Journal of Numerical Methods in Engineering, Special issue on Uncertainty Quantification and Prediction Science, Vol. 80, March 2009, pp.767-788.

Crespo L. G., Giesy D. P., Kenny S. P.; Reliability-based analysis and design via failure domain bounding, Structural Safety, 31, 2009, 306-315.

Horta L. G., Kenny S. P., Crespo L. G., and Elliot K. B.; NASA Langley’s approach to the Sandias’ structural dynamics challenge problem, Computational Methods in Applied Mechanics and Engineering, 197 (2008), 2607-2620.

Crespo L. G., Giesy D. P., Kenny S. P.; Robustness analysis and robust design of uncertain systems, AIAA Journal, Volume 46, Number 2 (February), 2008.

Crespo L. G., Kenny, S. P.; Reliability-based control design for uncertain systems, AIAA Journal of Guidance, Control and Dynamics 2005, Vol 28, No.4.

Crespo L. G., Kenny S. P., Giesy D. P.; A study of the safely recoverable flight envelope near stall. AIAA Guidance navigation and control conference, 13-16 August, 2012.

Crespo L. G., Giesy D., Kenny S. P.; Bounding of the failure probability range of polynomial systems subject to p-box uncertainties. ESREL 2012, Helsinki, Finland, 25-29 June.

Kenny S. P., Crespo L. G., Giesy D., Andrews L.; Robust control design for uncertain nonlinear dynamic systems IMAC XXX Conference and exposition on structural dynamics, Jacksonville, Florida, January 30-february 2nd, 2012.

Dorobantu A., Crespo L. G., Seiler P. J.; Robustness analysis and optimally robust control desing via sum-of-squares, AIAA multi-disciplinary optimization conference, 2012, Honolulu, Hawaii, 2012.

Crespo L. G., Kenny S. P., Giesy D. P.; Uncertainty quantification for polynomial systems via Bernstein expansions, AIAA non-deterministic approaches conference, 2012, Honolulu, Hawaii, 2012.

Crespo L. G., Munoz C. A., Narkawicz A., Kenny S. P., Giesy D. P.; Uncertainty analysis via failure domain characterization: polynomial requirement functions, ESREL 2011 Conference, 18-22 September 2011, Troyes, France.

Crespo L. G., Kenny S. P., Giesy D. P.; Uncertainty analysis via failure domain characterization: unrestricted requirement functions, ESREL 2011 Conference, 18-22 September 2011, Troyes, France.

 

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