Global-Equivalent Sliding Mode Control Method for Bridge Crane

A wide application of sliding mode variable structure control as a nonlinear robust method, has been witnessed in anti-swing positioning bridge crane system. Aiming at the problem that system is not approaching process, new Global-Equivalent Sliding Mode Controller (GESMC) based on proposed. This controller can realize anti-sway under condition uncertain model parameters and external disturbance. The proposed controller, different from traditional control, excels improving robustness through keeping states surface during whole response process. Specifically, it initiates with design global surface, which eliminate approach process achieve Afterwards, switching function combined equivalent method incorporated to effectively reduce chattering generated when reaches manifold. Its asymptotic stability proven without priori knowledge bounds unknown disturbances by using Lyapunov theory. Lastly, simulation conducted verifies effectiveness GESMC this paper meanwhile demonstrates comparatively favorable performance for reducing chattering.