Nonlinear Optimal Line-Of-Sight Stabilization with Fuzzy Gain-Scheduling

Authors: A. Puras Trueba, J. R. Llata García

Abstract:

A nonlinear optimal controller with a fuzzy gain scheduler has been designed and applied to a Line-Of-Sight (LOS) stabilization system. Use of Linear Quadratic Regulator (LQR) theory is an optimal and simple manner of solving many control engineering problems. However, this method cannot be utilized directly for multigimbal LOS systems since they are nonlinear in nature. To adapt LQ controllers to nonlinear systems at least a linearization of the model plant is required. When the linearized model is only valid within the vicinity of an operating point a gain scheduler is required. Therefore, a Takagi-Sugeno Fuzzy Inference System gain scheduler has been implemented, which keeps the asymptotic stability performance provided by the optimal feedback gain approach. The simulation results illustrate that the proposed controller is capable of overcoming disturbances and maintaining a satisfactory tracking performance.

Keywords: Fuzzy Gain-Scheduling, Gimbal, Line-Of-SightStabilization, LQR, Optimal Control

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1055138

References:

[1] B. D. O. Anderson, and J. B. Moore, Optimal Control Linear Quadratic Methods. Prentice Hall, 1990.
[2] J. P. Hespanha, "Lecture Notes on LQG/LQR controller design", 2005.
[3] J. M. Hilkert, "Inertially Stabilized Platform Technology", IEEE Control Systems Magazine, 2008.
[4] P. J. Kennedy, "Direct Versus Line of Sight (LOS) Stabilization", IEEE Transactions on Control Systems Technology, Vol. 11, No. 1, 2003.
[5] R. Palm and U. Rehfuess, "Fuzzy Controllers as Gain Scheduling Approximators", Fuzzy Sets and Systems, Vol. 85, 1997.
[6] L. Sciavicco and B. Siciliano, Modelling and control of robot manipulators, The McGraw-Hill Companies, Inc, 1996.
[7] K-J. Seong et Al., "The Stabilization Loop Design for a Two-Axis Gimbal System Using LQG/LTR Controller", SICE-ICASE International Joint Conference, Busan, Korea, 2006.
[8] S. Skogestad and I. Plostethwaite, Multivariable Feedback Control Analysis and Design, John Wiley & Sons, 2001, pp. 355-368.
[9] P. Skoglar, "Modeling and control of IR/EO-gimbal for UAV surveillance applications", Thesis, 2002.
[10] P. Wongkamchang and V. Sangveraphunsir, "Control of Inertial Stabilization Systems Using Robust Inverse Dynamics Control and Adaptive Control", Thammasat Int. J. Sc. Tech., Vol. 13, No. 2, 2008.
[11] B. Wu and X. Yu, "Evolutionary Design of Fuzzy Gain Scheduling Controllers", Proceedings of the Congress on Evolutionary Computation, 1999.