With the inertia force influencing when the trolley is in the acceleration or deceleration process, the loads and mechanical components will maintain the original state of motion and lag behind the trolley. So this kind of lagging behind will causes the loads and mechanical components move round the swing, that is, pendulum movement. This kind of movement is unfavorable. According to the sway control technology of overhead cranes, the main can be divided into mechanical sway control and electronic sway control.
Mechanical sway control is carried out though installing a guide column under the trolley frame. Though with stable and reliable advantages, the mechanical mechanism was complex and with high costs. The whole sway control process through the rigid structure of overhead cranes itself, with long working hours it might shorten the mechanical using time and increases the gap between the structures.
Electronic sway control can be divided into open-loop control and closed-loop control. Open-loop sway control sees the overhead cranes as a single pendulum model, by controlling the speed and acceleration of the overhead cranes to achieve its sway control. Closed-loop sway control sway control operations though adding special sensor or some electrical quantity to obtain the swing angle and angular velocity, in order to accurately control the trolley running direction and speed, to achieve the sway control purpose.
In summary, both mechanical sway control and electronic sway control have their own suitable applications. For some occasions which require high accuracy and with low efficiency requirement, mechanical sway control is highly recommended. And the electronic sway control suits for others which require high efficiency.