Internet laboratory tests control systems parameters
Students and faculty at the University of Tennessee at Chattanooga (UTC) are letting web users peer into the world of process control systems and dynamics at the Resource Center for Engineering Laboratories on the web at chem.engr.utc.edu/.This unique site is a server that allows users to run control experiments remotely over the Internet.
Students and faculty at the University of Tennessee at Chattanooga (UTC) are letting web users peer into the world of process control systems and dynamics at the Resource Center for Engineering Laboratories on the web at chem.engr.utc.edu .
This unique site is a server that allows users to run control experiments remotely over the Internet. Originally set up to serve only UTC students, the site now welcomes other users as well. It is supported by UTC's Center for Excellence in Computer Applications and by the National Science Foundation.
How it works
Upon accessing the site, users can run an experiment with controls or process dynamics. A system is selected to control pressure, temperature, voltage, flow, level, position, or speed. Then a function is selected—constant input, step input, sine input, pulse input, custom input, proportional feedback control, or proportional-integral feedback control.
Users then input their own parameters, configurations, and specifications. Clicking on the "Run Experiment" button generates results for each personalized experiment, along with custom output graphs in JPEG format.
According to Don Eberhart, R&D electrical engineer at UTC, this remote laboratory is set up using a main server, running Microsoft Windows NT, connected to five client machines each representing a different control system. Client machines communicate with the server using NT and client software written with LabView 5.0 from National Instruments (Austin, Tex.).
These remotely run experiments are turned into command files that are decoded by data acquisition cards, also from National Instruments. These cards produce variables that run actual physical control systems configured in a UTC lab. After an experiment is completed, a results file is written to the server, which creates a dynamic web page displaying these results back to the user.
Since the control systems run in real time with time delays between experiments, it is necessary for the server to "stack" commands from users in the order received. Thus, if more than one person tries to run an experiment at the same time, both experiments will not run at once. They will be run in sequence based on the order the commands reach the server. Users can view the list of waiting experiments waiting to see when their experiments will run.
Why it works
Jim Henry, professor of chemical engineering at UTC, says the remote lab was designed for those students who could not attend regular lab sessions, were at another campus without the necessary equipment, or needed extra help outside class. The web site allows students to do their remote experiments with real-time data, giving the same benefits as running the experiments on site.
Faculty members also benefit from the site. They can now demonstrate control experiments from anywhere in the world using no more than a computer with an Internet connection.
As for those outside the academic environment, Dr. Henry says that the site is available to anyone to use for educational, non-profit purposes.
Laura Zurawski, web editor firstname.lastname@example.org