plc和基于petri网培训三维虚拟汽车造型公园及控制.pdfVIP

PLCandPetriNetTrainingBasedona3DVirtualCarParkModelling and Control 1．Introduction The Bolognas declaration introduces, in the European Union Education Space, a significative change in the learning process, by changing the focusfrom aparadigm oriented to thetransmission toaparadigm oriented to the learning process. However, it is necessary to go further by introducing new tools thatmotivate and involve teachersand students in the learning process (Bourne 1995). Individual learning is the base conceptandpractice isnowadaysacommonanswer to industryrequirements (Kroumov 2003). One of the graduate automation lessons skills is to prepare students to develop PLC (Programmable Logic Controller) programs. The real PLC applicationsareapplied in severalindustrialdesigns (Culley2001).The student PLC programs can usually be tested in laboratories resorting to maquettes.A classical2D maquette connects to the PLC through wires and basically contains several switches and lights. A 3D maquette, based on hardware, is easier to perceive but harder to controland prototype. The movement of objects that emphasize the model and capture theattentionofstudentsisadifficulttask inahardwarebasedsolution. Evenmore,usually thereare severalgroups, forcing theuseofmore than one maquette at the same time. A virtual maquette is a tridimensional reconstruction of a model (industrialparts, buildings, cars , etc.) inside a computer containing realistic textures, lightning, different views stretching the distance from virtual to real (Foley 1995). The developed virtualmaquette is composedby a PC application, reducing some hardware problems and allowing an attractive visualization. The studentprogramming task isdoneresorting to development toolsprovided by the PLC manufacturers. This approach is better than a stand-alone simulationbecauseallowsstudentstopracticewitharealPLC,accessing to real hardware. The developed car parking maquet