Design of an emergency back-up system for overhead material handling operation

摘要

Electrical power failures in industries have caused various concerns on the use of overhead pick-and-place suction manipulator controlled by a programmable logic controller (PLC). This paper first examines the various types of emergency back-up systems used to overcome electrical power failure problems. It is found that the utilization of the compressed air remaining in the compressed-air pipeline of the factory and in the receiver of the compressor during the electrical power failure can provide cheap and effective way to overcome the problems. The paper then proceeds to discuss the design of a pure pneumatic emergency back-up system that was designed to immediately take over the control of the PLC-controlled suction manipulator in the event of an electrical power failure. With the objective of saving the object being transferred from falling off and causing damage and injury, a model was then built to test the design. It was found to be workable and effective.