Design And Research Of Tower Crane Control System Based On PLC

Since the reform and opening up,China's modernization process is accelerating.High rise buildings can accommodate the most rapidly growing population.The construction of tall buildings is the use of tower cranes to transport buildings on the ground to high-rise buildings.Tower crane in the construction of high-rise building has a pivotal position in the process.The tower crane has three kinds of operation,such as lifting,rotating,luffing operating mechanism.The tower crane can accurately convey the weight of the ground to the destination.At present,the domestic tower crane is the relay and the contactor electrical system control mode to control the tower crane operation of the three institutions.The traditional control system of tower crane based on relay contactor has many disadvantages,such as low reliability,high failure rate,difficult to check and remove the faults,lack of intelligence,short life and difficult maintenance.Therefore,it is of great significance to develop a set of high efficiency and reliable tower crane control system.According to the actual operation of the tower crane in the field,combined with the driving principle of the three operating mechanism of the tower crane,the paper designs a set of efficient and feasible electrical control system.The hardware design of PLC control system for tower crane is completed.The system adopts Koyo SH series of small PLC,three-phase AC motor,brake,rectifier,sensor etc..The working mechanism of the tower crane is controlled by a contactor and a relay.According to the selected electrical hardware design and manufacture of the PLC peripheral control circuit,the main circuit and system protection circuit,the three major motor control circuit and linkage control signal circuit.The software design of tower crane control system based on PLC is completed.The ladder diagram programming of the system mainly includes two aspects,the action procedure of tower crane and the communication program between PLC and SMS module.Two aspects of the tower crane action program design,including the action control procedures and system early warning program.The early warning program includes the limitation of the movement mechanism,the lifting weight and the lifting torque limit,and the automatic detection and automatic processing of the wind speed.Finally,the communication program between PLC and SMS module is mainly to achieve the remote lock and unlock,remote fault query and other functions.The company's users can remotely control the lock and unlock of the tower crane through the mobile phone short message,as well as the inquiry of the overload and super torque fault information.SMS remote control mode can avoid the use of tower crane in the process of non-standard operation or overdue use of arrears of rent.