(332h) Using Components in the Bag, Student Assemble and Run Simple Experiments in Undergraduate Lecture Course On Process Dynamics and Control

Using Components
in the Bag, Student Assemble and Run Simple Experiments in Undergraduate
Lecture Course on Process Dynamics and Control

Pál Tóth and
Mikhail Skliar

Chemical
Engineering, University of Utah

Last year, we completely transformed the instruction in an undergraduate
class on Process Dynamics and Control from the traditional approach,
consisting of lectures and homework assignments ? which occasionally include
computer simulations to test the designed controllers, etc. ? to a teaching
paradigm that emphasizes project-based learning. The subject of process
dynamics and control is difficult to teach because of the breadth of covered
topics, reliance on concepts expressed in a fairly formal manner, and the need
to teach students how to relate abstract concepts to the outcome of practical
designs. The undergraduate students often view this senior level course as an
abstract exercise in mathematics, and usually have difficulty applying
what they have learned to the actual process control. It was clear for a long
time that to bridge the theory and practice of process control, this course
would benefit from the addition of experimental projects. However, all previous
attempts at introducing experiments into this lecture course were only
marginally successful. For example, a few years ago we introduced projects that
used professionally designed educational experiments only to find out that time
sharing of the same equipment located in our instructional laboratory (Senior
Lab) is difficult and the value to learning based on a ?pre-packaged?
experiment was not that high. This ?experiment with experiments? was scrapped
the year after it was tried.

Our new approach is a concept of ?experiments in a bag.?  In
this approach, groups of three students receive a Ziploc bag of components,
including a low cost microcontroller, resistor, thermistor, transistors, etc.,
and are asked to put together their own experiments, which are small enough to
carry in a backpack and run at any continent time and location after connecting
the experiment to a laptop. It is assumed that students have no experience in
prototyping electronic systems but are capable of following basic bread
boarding instructions, such as those given at

http://implicit.che.utah.edu/Teaching/4203/GuideAssignment1.htm.
Students are asked to assemble a simple circuit shown in Fig. 1 which describes
a thermal control experiment in which the temperature of resistor R2 is
measured using thermistor R4. As part of the assignments, students are asked to:
(1) using the provided driver, establish the communication between the
microcontroller, which serves to acquire data and control an average current through
R2 using pulse-width modulation, and their Matlab code; (2) calibrate the thermistor
to provide temperature measurements of R2; (3) acquire test data and identify the
response models of the experiment, and (4) design and test simple temperature controllers
for the process.

Our
initial experience with the introduction of experiments into this traditional
lecture course is very positive and sets an example for future development of lecture
courses with incorporated experimental components. The ability for the student
to have an experiment that they implement themselves, carry in their backpacks,
and run at any convenient time and place are the key contributing factors to
the success. The students' own assessment of this new approach was remarkably
positive, despite a substantially higher workload needed to complete
experimental assignments.

Figure 1: Schematic of the student-assembled thermal control experiment