PLC-Based Tower Crane Torque Protection System

Torque protection is the core in tower crane’s safety monitoring system. The real-time protection system and software function in PLC were introduced. Using indirect addressing function, many two-dimensional data tables were accessed in PLC. The curves were fitted by linear interpolation method, the purpose of complex torque protection was achieved. This method can also be extended to other applications. As a complete system, the trolley position sampling and the calibration process were expatiated.