Program Design And Fault Diagnosis Of Control System In AS/RS

AS/RS (Automated Storage and Retrieval System) is an important part of modern logistics systems and is widely applied to every walk of life. Presently it has become one of the signs in enterprise production automation and management information. This work is originate from a modification project for an AS/RS that is an unfinished system, which has not been test systematically. The subsystems of the AS/RS can not work coordinately, their design is not finished off, and there are so many defects and defaults that this system may be caused to malfunction. Furthermore, the new procedure demands to reconstruct it and develop a PLC controlling program in order to optimize the procedure, minimize the default probability and improve the output and productivity.The conventional program design method is unable to solve the control problem of PLC control system with parallel, coordination, competition. To solve the problem, a PLC program design method based on Petri net is presented. Petri net is graphics model and is able to model for parallel system , so the program of PLC control system can designed conveniently and audio-visually. In the light of the design thoughts in the Petri net, this paper create the maths model adopting Function Chart, and on the basis of the model, begin to design PLC program of transportation system. This paper diagnoses the faults of the storage/retrieval machine as one of the key plants of AS/RS.A fault tree (FTA) is built based on the largely collected fault data. 'storage/retrieval machine could not be operated' is acted as the top event of the FTA and qualitative analysis of the FTA is done. The design of the fault-checking program of a storage/retrieval machine system has been complete combining the investigation of the fault phenomena in the AS/RS.The reconstruction and the design for the AS/RS based on the above method have been pass the testing and running and applied in practice. The designed objective has been achieved. The ideas and means have the instructive meaning for doing the similar projects.