Global-Equivalent Sliding Mode Control Method for Bridge Crane

Abstract

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

Modeling and control of overhead cranes: A tutorial overview and perspectives

“…Experimental results indicate that the SMC schemes are more robust than the other considered models. An SMC named "global-equivalent" has been introduced by [264] and compared with conventional SMC and the PID controller. The control is designed for the single-pendulum model with varying length links.…”

Nonlinear Enhanced Coupled Feedback Control for Bridge Crane with Uncertain Disturbances: Theoretical and Experimental Investigations

“…Consequently, the sliding mode control method, known for its robustness, has been widely applied to bridge crane control [14,24,25,34,39]. Particularly, Wang et al developed a full-course equivalent sliding mode controller to address the issue of the sliding mode approach stage robustness, which ensured that the system remained on the sliding mode surface and improved global robustness [28]. However, the convergence performance of this method depends on the sliding mode surface change state.…”

A novel model-free adaptive terminal sliding mode controller for bridge cranes

“…Therefore, a series of closed-loop control methods have been proposed, including model predictive control, 6 adaptive control, 7,8 output-feedback control, 9,10 intelligent control, [11][12][13][14] energy-based control [15][16][17][18] and sliding mode control. [19][20][21][22][23][24][25][26][27][28][29] The design of bridge crane control systems often involves the problems of model uncertainty, parameter perturbation and external interference in practical industrial applications, which can be solved by the sliding mode control efficiently. For example, a decoupling sliding mode control method was proposed in Yu et al, 22 which has been widely applied in various engineering domains owing to its simple structure and sensitive response.…”

“…Therefore, a series of closed-loop control methods have been proposed, including model predictive control, 6 adaptive control, 7,8 output-feedback control, 9,10 intelligent control, 11–14 energy-based control 15–18 and sliding mode control. 19–29…”

“…And a global sliding mode surface is established to ensure that the system state is located on the sliding mode surface from the beginning, which solved the problem of robustness in the approaching stage of the sliding mode. 24 However, the aforementioned sliding mode control methods can only ensure the gradual stability of the system instead of the guarantee of the finite-time convergence. Hence, in Chwa, 25 a fast terminal sliding mode control method was proposed, which not only guaranteed the finite-time convergence of the system, but also calculated its convergence time.…”