Fuzzy-PID Control In The Application Of Lifting 100m Rail System

In the actual operation, for the simple PID closed loop network control by PLC "and the crane" system, Brake and shift in the system start the process of acceleration and deceleration, the synchronization of two cranes is poor. Nevertheless, fuzzy control algorithm which has strong adaptability of control object parameter variation can ensure the fast response and less overshoot for the control system, but it has the disadvantage of static error remaining.A kind of fuzzy and PID switching algorithm which bases on switching control strategy has been proposed in this system for long rail lifting by combining the advantages of fuzzy control and PID control algorithm according to the real control engineering application. When displacement of the two cranes counterparts deviations (to set a threshold) is more larger ,fuzzy control for a wide range of adjustments in order to make response quickly; When displacement deviation is smaller and steady state process, adjusted by the PID, to eliminate static error and increase the control precision.Theory and design methods of fuzzy control and PID control algorithm are analyzed and their advantages and disadvantages have been summarized. The importance of the new algorithm which fuses the advantages of fuzzy and PID control algorithm has been illustrated. To reduce the complexity of calculation and to make the algorithm easy to use in embedded system ,a novel fuzzy and PID dynamic switching control algorithm to acquire the adaptability of control object parameter avriation.digital radio is used by the comnication of two bridge cranes. the network structure is PROFIBUS-DP, composition, distributed control system, and the selection of hardware and hardware configuration; software, mainly the configuration of PC, PLC and PLC, and communication between the PLC ; PID control program come from STEP7; Fuzzy control procedures for the preparation modular design.