Fuzzy-PID Control In The Application Of Lifting100m Rail System

In the actual operation, for the simple PID closed loop network control by PLC "and thecrane" system, Brake and shift in the system start the process of acceleration anddeceleration, the synchronization of two cranes is poor. Nevertheless, fuzzy controlalgorithm which has strong adaptability of control object parameter variation can ensure thefast response and less overshoot for the control system, but it has the disadvantage of staticerror remaining.A kind of fuzzy and PID switching algorithm which bases on switching control strategyhas been proposed in this system for long rail lifting by combining the advantages of fuzzycontrol and PID control algorithm according to the real control engineering application.When displacement of the two cranes counterparts deviations (to set a threshold) is morelarger,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, toeliminate static error and increase the control precision.Theory and design methods of fuzzy control and PID control algorithm are analyzedand their advantages and disadvantages have been summarized. The importance of the newalgorithm 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 embeddedsystem,a novel fuzzy and PID dynamic switching control algorithm to acquire theadaptability of control object parameter avriation.digital radio is used by the comnication of two bridge cranes. the network structure isPROFIBUS-DP, composition, distributed control system, and the selection of hardware andhardware configuration; software, mainly the configuration of PC, PLC and PLC, andcommunication between the PLC; PID control program come from STEP7; Fuzzy controlprocedures for the preparation modular design.