Modelling and simulation of electrical differential driving system for bridge grab unloader

In this paper, the focus is a bridge grab unloader that is one of the most important load-unload equipments in harbour. By applying the second Lagrange equations in analysis dynamic, mathematics model of electrical differential driving system is built. The study target belongs to a kind of three freedom system, which also is non-linear, coupling and multi-variable. The control manner which comprises negative-feedback of differential is provided. Subsequently the simulation model be constructed. Based on simulation model, this paper furtherly analyses characteristic of swing of grab, and then introduces a sort of method for swing-restrain problem. The paper testifies that it is feasible that driving grab is achieved by electrical differential driving system.