Abstract: Aimed at the problems of time delay and laborsome work of programming of PLC to implement fuzzy PID control algorithm in anti-sway control system of suspensory device of crane, a design idea of applying embedded-type system to control the anti-sway system of crane is proposed. The system adopts host-slave control mode, in which the embedded-type processor is set to the slave working mode and the PLC is set to the host working mode; the slave is responsible for the sampling of the crane suspensory device parameters and the running of fuzzy PID control algorithm. According to the calculation result of slave operation, the host is responsible for control the speed and direction of the crane trolley motor. Through the coordinated control of the host and slave operation, the purpose of anti-swaying of crane suspensory device can be realized. RS485 is a serial communication interface that ensures the reliable communication of the data between the host and the slave. The fuzzy PID anti-sway control algorithm is run on the embedded-type processor computing platform with C-programming. The program is simple, and the processor performs instructions of reading and writing operations in short period. This design method improves the ability of the system to process data and control efficiency of the system. The control mode with embedded-type processor as the host and the PLC as the slave increases the flexibility of the system structure. Meanwhile, the system combined with the fuzzy PID algorithm has strong robustness.

Key words: crane, electronic anti-swaying, master-slave control, PLC, embedded-type system, fuzzy PID