Pilot Induced Oscillations Adaptive Suppression in Fly-By-Wire Systems
The present work proposes the development of an adaptive control system which enables the suppression of Pilot Induced Oscillations (PIO) in Digital Fly-By-Wire (DFBW) aircrafts. The proposed system consists of a Modified Model Reference Adaptive Control (M-MRAC) integrated with the Gain Scheduling technique. The PIO oscillations are detected using a Real Time Oscillation Verifier (ROVER) algorithm, which then enables the system to switch between two reference models; one in PIO condition, with low proneness to the phenomenon and another one in normal condition, with high (or medium) proneness. The reference models are defined in a closed loop condition using the Linear Quadratic Regulator (LQR) control methodology for Multiple-Input-Multiple-Output (MIMO) systems. The implemented algorithms are simulated in software implementations with state space models and commercial flight simulators as the controlled elements and with pilot dynamics models. A sequence of pitch angles is considered as the reference signal, named as Synthetic Task (Syntask), which must be tracked by the pilot models. The initial outcomes show that the proposed system can detect and suppress (or mitigate) the PIO oscillations in real time before it reaches high amplitudes.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1474489Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 386
 Department of Defense Interface Standard. Mil Standard, MIL1797A: Flying qualities of piloted airplanes. Washington D. C., 1995.
 I. L. Ashkenas, H. R. Jex, D. T. Mcruer, Pilot-induced oscillations: their cause and analysis. Systems Technology Inc Inglewoodca, 1964.
 J. W. Smith, D. T. Berry, Analysis of longitudinal pilot-induced oscillation tendencies of YF-12 aircraft. 1975.
 M. R. Anderson, Pilot-induced oscillations involving multiple nonlinearities. Journal of Guidance Control and Dynamics, vol. 21, no. 5, pp. 786- 791, 1998.
 B. Etkin, L. D. Reid, Dynamics of flight stability and control, 3rd Edition, pp. 93-128, New York: New York Wiley, 1996.
 H. C. Moura, G. S. P. Alegre, J. H. Bidinotto, E. M. Belo, “Pio susceptibility in Fly-By-Wire systems (Accepted for publication)”, 31st Congress of the International Council of the Aeronautical Sciences, to be published.
 A. Tustin, The nature of the operator's response in manual control, and its implications for controller design. Journal of the Institution of Electrical Engineers-Part IIA: Automatic Regulators and Servo Mechanisms, vol. 94, no. 2, pp. 190-206, 1947.
 D. T. Mcruer, E. S. Krendel, Mathematical models of human pilot behavior. Advisory Group for Aerospace Research And Development. Neuilly-SurSeine (France), 1974.
 D. T. Mcruer, D. Graham,E. Krendel, W. Reisener, Human pilot dynamics in compensatory systems. Air Force Flight Dynamics. Lab. AFFDL-65-15, 1965.
 A. A. Ghaffar, T. Richardson, Model reference adaptive control and LQR control for quadrotor with parametric uncertainties, World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, vol. 9, no. 2, pp. 244-250, 2015.
 L., Eugene, W. Kevin, Robust and adaptive control with aerospace applications, 1st Edition, London, Springer, pp. 281-292, 2013.
 V. Stepanyan, K. Krishnakumar, MRAC revisited: guaranteed performance with reference model modification, American Control Conference (ACC), IEEE, pp. 93- 98, 2010.
 V. Stepanyan, K. Krishnakumar, On the robustness properties of M-MRAC. [email protected] Aerospace, pp. 2407, 2012.
 D. G. Mitchell, A. J. Arencibia, S. Munoz, Real-time detection of pilot-induced oscillations, AIAA Atmospheric Flight Mechanics Conference and Exhibit, Providence, Rhode Island, pp. 4700, 2004.
 D. A. Johnson, Suppression of pilot-induced oscillation (PIO). Air force Inst. of Tech Wright-Patterson, Afb. OH School of Engineering and Management, MSc Thesis, 2002.
 Q. Liu, Pilot-induced oscillation detection and mitigation, Cranfield University, School of Engineering, Department of Aerospace Engineering, MSc Thesis, 2012.
 K. J. Astrom, B.Wittenmark, Adaptive control. 2ª Ed. Reading, Mass: Reading, Mass. Addison-Wesley,1st edition, pp. 390-442, 1934.