The Development Of PLC Control Software For Packaging Machinery Based On MBD

Most of today’s packaging machinery are non-standard machinery, they have so many function modules and there is always high coupling and frequent communication between each module. Meanwhile, the control logic is complex and trivial, leading to a high requirement of reliability and time sequence of the control system. However, each development stage is isolated in traditional PLC software development, so programming and debugging is time-consuming, which couldn’t meet the requirements of rapid prototyping, and always lead to a series of unnecessary manual coding errors. Therefore, it is important to develop PLC control software of high reliability in a simple, rapid, and efficient way.So, the PLC controlling software is developed using Model Based Design(MBD) for Material Bagging System in this thesis, exploring a formalized method concerning on complex packaging machinery. My work is as follows:(1) Designing of the electrical hardware platform of the prototype. Both of the electrical principle diagram and electrical schematic diagram of the Material Bagging System are designed in Solidworks Electrical.(2) Designing of the PLC software architecture of the Material Bagging System. The problem of how to decompose a complex controlling system is solved, with the result of several Function Blocks. With programming language standard of IEC61131-3 as theorectical guidance, the software model and function model of the whole controlling system are established. And the PLC controlling software of Material Bagging System is decomposed, step by step, to get the smallest Program Organization Unit(POU)-- Program, Function Block and Function. Then the interfaces, sequence diagrams and finite state machine of each Function Block are defined.(3) Taking 2 function blocks – StartAndStop and ShangDai as examples, the Stateflow model of each function block is established in Matlab/Stateflow. Then the model is checked, verified and successfully simulated, meeting the controlling requirements.(4) In the end, the PLC code is generated automatically, and the problem of Timer in generated code is solved. Then a project is eatablished in the Schneider IDE--So Machine, and the generated code is simulated successfully.