PLC Programming Handbooks
Impressive Student Control Projects
Lately I've run across some very cool PLC control projects done by university students that I'd like to share.
A couple of examples come from the Introduction to Programmable Logic Controllers in a Mechanical Engineering Instrumentation Course taught at the University of Alabama. It sounds like a really neat hands on environment for some practical learning about PLCs and control systems. The document outlines development of a PLC test stand for the class using an Automation Direct DL205 PLC with several pneumatic cylinders, solenoid valves, proximity sensors, pressure regulators, DC power supplies which are mounted on a peg board.
The really fun part comes with two of the senior projects. In practice they are great examples of assistive technology. One is a page turning device using an Automation Direct DL05 and parts that were scavanged from an old dot matrix printer.
Equally impressive is a DL05 that can fish by casting and reeling a fishing rod.
It's amazing what those little DL05s can do.
Ball on Plate
This next project by Kenn Sebesta doesn't use a PLC but it certainly deserves a mention. For his masters thesis at UniversitÃƒÂ© de Bourgogne in Dijon, France he developed a Ball and Plate Doohicky using legos.
If you're not impressed then you have to watch the video. The computer controls the plate and moves the ball around to any specific spot without it falling off. This is a great job demonstrating an open-loop control which is hard enough in one direction yet he's doing it in 2-d.
Equally impressive is his A-D converter the hard (but cheap!) way. This was developed for the above system. I wouldn't call it cheap but it is cool.
The Crazy J guitar playing machine project was created as a part of the Georgia Tech graduate Mechatronics class, by Jason Lawrence, Turner Howard and Susan Knueven. In brief, this device uses a HC11 Motorola Micro-controller to convert a MIDI file into the electrical signals needed to drive solenoids that pluck the strings. Check out the sound clips! This thing does a better job playing Layla then I do ;-)
A computer built out of relays is not the brain child of a student but a professor, Harry Porter, at Portland State University. It is certainly a great teaching tool to realize how computers used to work and still do at a very basic level. Just think if we didn't have PLCs then this is the type of menagerie of relays that control systems technicians would be troubleshooting. At least it would be better then using a Babbage difference engine built out of Legos!
It uses 415 relays, 111 switches, 350 LEDs using a mere 160 watts. All the specs are on the site. Don't miss the movies of the relay computer in action. If you don't have the bandwidth at least listen to the sound clip of those relays clickin' away.
What will those crazy kids think up next?
If you have any similar examples please register and post them in the comments.