Design And Implementation Of Anti-Shake Control System For Grab Ship Unloader

The grab ship unloader is the important equipment, which is utilizedload and unload at harbors. It is urgent to develop new technologies to reduce the workers’ working strength and increase the productivity, reliability and safety.The anti-shake control system of the ship unloader in the semi-automatic, fully automatic operation is studied in the thesis. The reliability, safety and efficiency of the equipment are improved by employing precise programming control to shorten the time for the pendulum and the single working cycle.The six working stages are mainly concerned by analyzing the operation rules of the grab and the trolley. A mathematical model is firstly established on the basis of the theoretical and operational experience. The best time-controlling method to achieve the target position is calculated based on the optimal control theory. Each stage is controlled by using the acceleration and deceleration techniques to get a useful acceleration matching horizontal output of the trolley and straight rising of the ship unloader. According to the two processes to accelerate,the control method is presented in the loading and unloading of anti-shake stage. Meanwhile, the semi and fully automatic control system is developed with the design of hardware and programming language from the mathematical model by the practice of specific projects according to the selection of frequency converter, PLC, coder, etc.The anti-shake control system of the device was used in unloader (Model ZQX1850t/h) Lianyungang. The expected goal can be reached. It can not only eliminate the swing and increase the reliability and safety of the system, but also reduce the cycle time and improve labor productivity in order to optimize the cycling operating process of the ship unloader.