Control Theory Tech, Vol. 15, No. 1, pp. 34–44, February 2017 Control Theory and Technology http://link.springer.com/journal/11768 Local model networks based mixed-sensitivity H-infinity control of CE-150 helicopters Mohamed Redouane KAFI 1,4† , Hicham CHAOUI 2 , Suruz MIAH 3 , Abderrazak DEBILOU 4 1.Laboratoire de G ´ enie Electrique (LAGE), Universit ´ e Kasdi Merbah Ouargla, Ouargla, Algeria; 2.Center for Manufacturing Research, Department of ECE, Tennessee Technological University, Cookeville, TN, U.S.A.; 3.Department of Electrical and Computer Engineering, Bradley University, Peoria, IL, U.S.A.; 4.Faculty of Sciences, Department of Electronics, Biskra University, Algeria Received 17 July 2015; revised 2 June 2016; accepted 2 June 2016 Abstract In this paper, a local model network H-infinity control is proposed for CE-150 helicopter stabilization. The proposed strategy capitalizes on recent developments on H-infinity control and its promising results in robust stabilization of plants under unstructured uncertainties. CE-150 helicopters are known for their varying operating conditions along with external disturbances. Therefore, local model networks are introduced for their adaptive feature and since they provide a powerful combination of fuzzy logic and conventional linear control techniques to control nonlinear systems without the added computational burden of soft-computing techniques. Using the fact that the system can be linearized at different operating points, a mixed sensitivity H-infinity controller is designed for the linearized system, and combined within a network to make transitions between them. The proposed control structure ensures robustness, decoupling of the system dynamics while achieving good performance. A comparison is carried-out against the well-known proportional-integral-derivative (PID) control technique. Results are presented to illustrate the controller’s performance in various operating conditions. Keywords: H-infinity control, helicopter, local model network, robust stabilization DOI 10.1007/s11768-017-5073-x 1 Introduction Helicopters have received a thorough attention and have been extensively used lately to demonstrate the effectiveness of different kinds of controllers. They are considered as a well-established benchmark challenge for many control problems and have been used in va- rious applications such as transportation, and above- ground monitoring [1, 2]. Varying operating conditions along with structured and unstructured uncertainties, such as external disturbances, are among the numer- ous challenges that need to be addressed to success- fully control such highly complex nonlinear unstable † Corresponding author. E-mail: kafi.redouane@univ-ouargla.dz. Tel.: +213662091913. © 2017 South China University of Technology, Academy of Mathematics and Systems Science, CAS, and Springer-Verlag Berlin Heidelberg