Vibration suppression control of a flexible arm using a nonlinear observer with simultaneous perturbation stochastic approximation

Abstract

The main objective in this study is the vibrational control of a one-link flexible arm system. A variable structure system (VSS) nonlinear observer has been proposed in order to reduce the oscillation when controlling the angle-of the flexible arm. The parameters of the nonlinear observer are optimized using a modified version of the simultaneous perturbation stochastic approximation (SPSA) algorithm. The SPSA algorithm is especially useful when the number of parameters to be adjusted is large, and makes it possible to estimate them simultaneously. For the vibration and position control, a model reference sliding-mode control (MR-SMC) has been proposed. The MR-SMC parameters are also optimized using a modified version of the SPSA algorithm. The simulations show that vibrational control of a one-link flexible arm system can be achieved more efficiently using our method. Therefore, by applying the MR-SMC method to a nonlinear observer, we can improve the performance in this kind of model using our proposed SPSA algorithm, and we can determine the control parameters very easy and efficiently.