Bridge crane motion control of power control systems are relying on the crane bridge type crane trolley run institutions and bodies so that the combination of goods transported in a rectangular plane movement. Crane movement is driven hoisting mechanism, operating mechanism, slewing and luffing mechanism. To achieve these movements, and these bodies put under load, the crane must have sufficient strength and rigidity of the metal structure, a drive mechanism movement and motion control of the power control system; And, in order to ensure safe and reliable operation of the crane safety and signal indicating means. Crane features are: short-period cycle operation. A work cycle include: extract, lifting and running by unloading points, down, unloading, and then return empty place. A work cycle time is generally long as tens of seconds to several minutes species, the longest no more than one or twenty minutes. This feature is its choice of power plant capacity is calculated and electrical equipment have a greater impact. Frequent starting, braking causes the drive mechanism and the metal structure strong impact and vibration, resulting in a large dynamic loads, because this load is very smooth, which makes the strength and fatigue calculation becomes more complicated. In addition, for bulk materials handling crane, the production efficiency is a very important performance indicator, which depends not only on the velocity of the bodies, but also on the auxiliary time for loading material size. So for speed, acceleration, motion degree of overlap, extract and discharge the choice of the degree of automation should be carefully considered.