Application Research in Trolley Safety Control System of Quay Side Container Crane with PLC

This paper discusses new trolley safety control system with PLC based on the original relay control system to act as fault diagnosis and protection control. New PLC system uses new encoder detecting motor speed and realize speed loop controller to increase the timing performance. At the same time, PLC collects information of local system, diagnosis the running status, fault, calculates the motor model to get simulated speed besides the encoder, and save the date before fault for replaying and analysissing. Any way, series problems will cause PLC output to stop the system running. The multi model control makes the system more safe and more applicable.