A Blended Sliding Mode Control with Linear Quadratic Integral Control based on Reduced Order Model for a VTOL System Marco Herrera 1 , Paulo Leica 1 , Danilo Chavez 1 and Oscar Camacho 1,2 1 Departamento de Automatizaci´ on y Control Industrial, Escuela Polit´ ecnica Nacional, Ladr´ on de Guevara E11-253, Quito, Ecuador 2 Facultad de Ingenier´ ıa, Universidad de los Andes, M´ erida, Venezuela Keywords: Sliding Mode Control, LQI, Reduced Order Model, ISE Index, VTOL System. Abstract: In this paper, a Sliding Mode Control with chattering reduction based on reduced order model using Linear Quadratic Integral Control as sliding surface, is implemented to One Degree of Freedom Vertical Take-Off Landing System (VTOL). The controller performance is measured using Integral of the Square Error index by simulation and real tests. Finally, the Sliding Mode Control with a Linear Quadratic Integral Control as sliding surface performance for reference tracking and, robustness against VTOL system physical parameter uncertainties and external disturbances are verified by experimental results. 1 INTRODUCTION The Sliding Mode Control (SMC) is a robust con- troller that deals with high-order nonlinearities, which has been extensively studied due to its ability to re- ject disturbances (Han et al., 2016; Nawawi et al., 2011), and low sensitivity to uncertainties in the pa- rameters (Prusty et al., 2016), thus it eliminates the necessity of an accurate model of the system (Sa- banovic et al., 2004). An LQI controller is a Linear- Quadratic Regulator (LQR) with integral action. The LQI advantages are: simple implementation (Carri` ere et al., 2008), best possible performance according to the minimization of an index, with a compromise be- tween the response of the variables and the control effort that guarantees the stability of the system (Mo- hammadbagheri et al., 2011). In order to achieve a robust control system with the best performance, the advantages of the SMC and LQI controllers can be blended in an robust-optimal controller. In (Dong et al., 2011), an optimal slid- ing mode control for nonlinear systems with uncer- tainties is designed, where system stability is ensured by minimizing a performance index. In (Teimoori et al., 2012), an optimal sliding surface with respect a quadratic performance index is selected for a system where the parameters uncertainties are considered. In (Chithra and Koshy, 2016), an integral action LQR is combined with a robust SMC for a Twin MIMO Ro- tor system, which is evaluated and compared with PID and LQI controllers using simulations. In (Zhang et al., 2014a), the combination of a method to decouple the dynamics of the VTOL air- craft system and a SMC is presented. The perfor- mance of the designed controller and the tracking pro- cess are shown with simulation results. In (Mondal and Mahanta, 2013), a second order sliding mode is presented and a sliding surface is designed by an adaptive gain tuning mechanism for stabilizing a sin- gle degree of freedom VTOL system. In this article a robust-optimal controller based on Sliding Mode Control with integral action (SMC- LQI) is designed and implemented on VTOL system. The sliding surface with an optimal criterion by mini- mizing of a performance index is chosen. The design of the controller is based on a reduced order model of the VTOL system, which allows that implementation in the real system to be simple. This paper is orga- nized as follows. In Section I, a simplified dynamic model of One Degree of Freedom (1-DOF) VTOL is described. Section II, a SMC controller with re- duction of the chattering effect is designed, where the sliding surface is chosen via LQI controller approach. In Section III, the performance of the controller is ver- ified by the simulation results. In Section IV, the im- plementation of the proposed controller on the real platform for experimental tests are shown. Finally the conclusions are presented in Section V. 606 Herrera, M., Leica, P., Chávez, D. and Camacho, O. A Blended Sliding Mode Control with Linear Quadratic Integral Control based on Reduced Order Model for a VTOL System. DOI: 10.5220/0006429606060612 In Proceedings of the 14th International Conference on Informatics in Control, Automation and Robotics (ICINCO 2017) - Volume 1, pages 606-612 ISBN: 978-989-758-263-9 Copyright © 2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved