SIMULATIONS OF A REST-TO-REST MOTION IN OVERHEAD TRAVELLING CRANE WITH TWO INTERMITTENT FEEDFORWARD FUNCTIONS FOR SUPPRESSING RESIDUAL VIBRATION

Abstract

In this paper, two intermittent feedforward functions, called posicast shaped function (PSF) and vibration manipulation function (VMF), are compared to suppress residual vibration of an undamped oscillator, such as an overhead travelling crane. The conditions of posicast shaper are limited, such as intermittent operational period, no feedback control, constrained application for a one-time rest-to-rest motion and requirement of an original command. On the other hand, operational period of VMF is not restricted into an integer times of the natural period of the target oscillator. Since VMF can make the object into the arbitrary aimed state after each operation, the remaining vibration can be additionally suppressed by the next operation under discrete sampled-data control. In this study, we will simulate to control an overhead travelling crane for a rapid rest-to-rest transfer by using these methods under certain noises or non-linearity. We will show advantages of VMF for the suppression of residual vibration in these circumstances.