Vibration Control of an Overhead Crane by Elimination of the Natural Frequency Component

(Application to double pendulum type system)

Abstract

The aim of this study is to develop a systematic method to suppress residual vibration in overhead cranes that lowers operating performance and prevents automation of the system. In the previous paper, we proposed a control method which is based on the fact that residual vibration is completely suppressed in a linear undamped system excited by an external force that does not contain the natural frequency component of the system. The proposed method introduces the concept of the apparent external force which includes the influence of nonlinearity and damping, making it applicable to single pendulum type nonlinear damped systems as well as linear undamped ones. However, if mass of the hook is too large to be neglected, the single pendulum type system is not suitable to model cranes. Therefore, this paper uses double pendulum type system model of crane, and suppressing the residual vibration by eliminating two natural frequency components from each the apparent external force. Numerical simulations demonstrate that this method can suppress the residual vibration of the double pendulum type system. Furthermore, optimizing trajectory decreases the maximum swing angle of the hook and the cargo during transportation and makes transition of the maximum swing angle with control time smoothly.