Lab courses go virtual

Thomas F. Edgar, University of Texas -- Control Engineering, 12/1/2005

A number of universities have maintained a dedicated laboratory course as part of the process control sequence, but those numbers have been shrinking due to the high resource requirements of lab courses and the pressure to reduce the number of hours in the engineering curriculum. While some chemical engineering departments run a junior measurement lab and a senior unit-operations lab, many now operate only one lab in the senior year which may incorporate control-related experiments. Laboratory courses are evolving, and new directions are being examined at specific universities, combining elements of simulation and also distance learning.

In the chemical process industries, the high cost of pilot scale equipment and operating personnel has led to greater reliance on computer-based simulations rather than traditional pilot-scale experiments. Consequently, today's engineers work more often from a control room or from behind a computer screen. Now, you rarely find engineers in the field adjusting valve positions, flow rates, and temperatures. Typically, this is done using the computer interfaces of distributed control systems.

The fourth-year unit-operations laboratory at Texas Tech University is emulating this practice by producing computer-generated simulations based upon mathematical models for the pieces of equipment in the laboratory. This permits experimentation and simulation. The unit-operations laboratory can familiarize students with the safety concerns and operational issues of each piece of equipment. A Virtual Unit Operations Laboratory (VUOL) complements the existing physical laboratory to give the students a realistic experience of industrial operations. National Instruments' LabView computer-interfaces of the VUOL give students an experience of controlling the equipment via the computer in addition to physically turning valves and checking temperatures.

Another approach being employed involves the use of a computer connected to the Internet to allow students to carry out experimental studies in a remotely located physical laboratory. Permitting students to operate real laboratories at any time, from anywhere, using standard, digital communication software such as Web browsers is a burgeoning topic as interest increases in remote control and maintenance. This approach also permits a teacher and students at another institution to have access to laboratory facilities without incurring the cost of equipment maintenance and technician or teaching-assistant support.

Remote laboratory capability is available in the laboratories at the University of Tennessee at Chattanooga (UT-C), the University of Texas at Austin, and the Massachusetts Institute of Technology, as well as other schools. The UT-C laboratory station's computer operates equipment (such as pumps, valves, heaters, and relays), collects the data (such as pressure, temperature, and concentration) and sends data to the user via Internet. From the Web browser, students can link to tutorials, pictures, live videos, and past data files related to the equipment set-up. Graphs of the time-progress of all process variables are also separately available on the Web. These Web pages can be viewed simultaneously by other students or instructors in real time, with the raw data archived for subsequent viewing and analysis.

Several universities have used the UT-C facility via the Internet for undergraduate laboratory experiments. The use of simulations and remote laboratories is expected to increase in the future, although many faculty, at present, do not readily embrace such changes.