Distributed Control Nodes for Material Flow System Controls on the Example of Unit Load Conveyor and Sorter Facilities

The Chair of Transportation and Ware-housing at the University of Dortmund together with its industrial partner has developed and implemented a decentralized control system based on embedded technology and Internet standards. This innovative, highly flexible system uses autonomous software modules to control the flow of unit loads in real-time. The system is integrated into Chair’s test facility consisting of a wide range of conveying and sorting equipment. It is built for proof of concept purposes and will be used for further research in the fields of decentralized automation and embedded controls. This presentation describes the implementation of this decentralized control system.

Simulation and analysis of an emergency lowering system for crane applications

An emergency lowering system for use in safety critical crane applications is discussed. The system is used to safely lower the payload of a crane in case of an electric blackout. The system is based on a backup power source, which is used to operate the crane while the regular supply is not available. The system enables both horizontal and vertical movements of the crane. Two different configurations for building the system are described, one with an uninterruptible power source (UPS) or a diesel generator connected in parallel to the crane’s power supply and one with a customized energy storage connected to the intermediate DC-link in the crane. In order to be able to size the backup power source, the power required during emergency lowering needs to be understood. A simulation model is used to study and optimize the power used during emergency lowering. The simulation model and optimizations are verified in a test hoist. Simulation results are presented with non-optimized and optimized controls for two example applications: a paper roll crane and a steel mill ladle crane. The optimizations are found to significantly reduce the required power for the crane movements during emergency lowering.