SLIDING MODE CONTROL VIA ALQR FOR UNCERTAIN SYSTEMS: AN LMI APPROACH
RENAN LIMA PEREIRA1; RUBENS JUNQUEIRA MAGALHÃES AFONSO11; Karl Heinz Kienitz1
1 ITA
doi:10.20906/CPS/COB-2015-1848
Resumo
This paper proposes a robust nonlinear control design strategy for a class of systems with parametric uncertainties. Linear Matrix Inequality (LMI) conditions are derived in order to obtain a nonlinear controller that ensures stability and performance of the closed loop system. The design problem has been formulated using a consistent framework for robust Sliding Mode Control (SMC) via Amplified Linear Quadratic Regulator (ALQR). Typically, systems with standard ALQR controllers present enhanced stability margins. However, the standard ALQR does not ensure robust stability when model uncertainties are incorporated. In order to solve this problem, a novel method using the SMC via ALQR is provided. The effectiveness of the design method was evaluated considering a system with two cars connected to each other through a linear spring, with only one actuator. The control objective is to track reference trajectories and ensure performance and stability in spite of disturbance, noise and unmodeled dynamics (static friction). The experiments showed that nonlinear controllers using SMC via ALQR based on LMIs may lead to advantageous results over classical design methods.
Palavras-chave: Nonlinear Control; Sliding Mode Control via ALQR; LMI; Parametric Uncertainties