Bucket wheel excavators
A bucket wheel excavator is the most famous symbol of heavy machinery for open-pit mines. It‘s designed for material extraction (mining) and its construction is adapted to it. Control system is used as a brain of the machine and its objective is to control and monitor the machine. The PLC is placed at the excavator and controls all of its movements. Controlling of travel is a basic movement to move machine from one place to another. During the mining process, a slew, a boom lift and the bucket wheel are also controled by the PLC. Excaveted material is taken off by conveyor belt, which is controlled by PLC as well. Many of these movements are controlled by frequency changers or softstarters through the PLC. Supervising functions of PLC are focused on monitoring level limits such as position of moving parts, temperature limits and liquid levels, as next, technology failure detection with assistance of feedback signals, measuring and counting various data for example indicative amount of excavated material and operating hours of individual drives. The control system includes visualisation (generally two or multi-screen), where are displayed the necessary data for operating the excavator and allows to set certain machine parameters. If is necessary, the control system may hold even higher features as a extraction management software according to pre-specified parameters.