Robust control of rotary cranes under rope length variance via LMI optimization

Because natural frequency of the rope-load oscillation system affects the stability and performance of the control system, the controller design should consider robustness with respect to rope length. If the control system considers the effect of rope length variance, the crane´s motion can be controlled without a sensor system for measuring it. This paper presents a control method based on linear matrix inequality optimization for achieving robustness with respect to rope length variance. Simulations results demonstrate the effectiveness of the proposed method.