A Novel Sliding Mode Control Method for Tower Crane Systems by Employing Beneficial Disturbance Effects

Abstract

AbstractA novel sliding mode control method, as is shown in this paper, is proposed for the 4-DOF tower crane system by employing beneficial disturbance effects to enhance the transient control performance as well as to ensure the strong robustness simultaneously. More precisely, we deliberately construct a nonlinear disturbance observer, and then, the advantages and disadvantages of the disturbance influence on the 4-DOF tower crane system are described by a constructed disturbance effect indicator (DEI) based on the observation information. Subsequently, the novel sliding model control method is designed in the light of the estimated disturbance and the introduced DEI. Additionally, the stability of the closed-loop system is demonstrated by Lyapunov techniques. It should be pointed out that the designed method points out that besides bad effects, disturbance has the desirable side-effect of transient control performance improvement, and as a result, introducing desirable side-effect into the controller design is of great importance. The effectiveness and robustness of the designed sliding model control method can be demonstrated by simulation results.KeywordsDisturbance effect indicatorTower cranesRobustnessTransient control performanceSliding mode controlDisturbance observer