Independent Minds, Working Together

Robots Express ‘Human Side’ in Physics Class Demonstration

Students in “Electronics for Scientists” use sensors to bring automated devices to life

19 December, 2013 by John Finn

WOOSTER, Ohio — An industrious quartet of robots revealed glimpses of human-like behavior as they carried out their assigned tasks on the final day of the semester in Shila Garg's Electronics for Scientists class (Physics 220) at The College of Wooster.

"Spot-Bot," "Mine Sweeper," "Tuning-Bot," and "Li'l B the Bridge Bot" squared off in a spirited demonstration before a standing-room only gathering in Room 101 of Taylor Hall earlier this month.

The biennial event, established by Emeritus Professor of Physics Don Jacobs more than a decade ago, drew students, faculty, and staff from a range of departments and offices across campus.

"Our students have done a wonderful job," said Garg. "I can't tell you how hard they worked on this process. It's a story of intellectual ability, perseverance, and hard work." Indeed, at least one group of students pulled an all-nighter to make sure their robot was ready for the big stage.

The semester-ending assignment called for the students to create a robot using a kit by Lego Mindstorms NXT, and equip it with a sensor programmed to react to something in the environment (similar to a human responses to sight, sound, or touch), but Garg made it clear that this exercise was far more than a simple science project. "What they did was most impressive," she said. "It took a great deal of creativity and critical thinking."

Student teams had to design their own sensor and build it, write their own computer program, and communicate the program to the robots, according to Garg. "There are many reasons why something in the circuit or the program may not work correctly," she said. "I could simply be a (faulty) electronic component or the sensor not having enough sensitivity to detect something. "

The session began with "Spot-Bot," a metal-detecting robot programmed by junior Jai Ranchod and sophomore Matt King-Smith, which was designed to sense the difference between ferromagnetic and paramagnetic metals. The robot was instructed to turn to the right when it sensed one metal and to the left when it sensed the other. Despite some challenges with the flow of voltage, "Spot-Bot" was, for the most part, spot on in its discernment.

"Mine-Sweeper," developed by sophomores Calvin Milligan, Nate Mathewson, and Nate Stone, was constructed to detect concealed magnets located at various positions on a tabletop surface. While not as dangerous as detecting mines, this robot had to be equally vigilant, using two magnetodiode sensors that detect magnets based on which one detected the greater voltage increase, at which point it would drop a marker closer to one diode or the other. In the end, "Mine-Sweeper" carefully canvassed the tabletop and successfully identified the magnets below.

"TuningBot," was designed by senior Ben Harris, junior Shawn Bowman, and sophomore Trent Ziemer, to lend an "ear" to sound. Constructed with a mechanical string winder, a sensor circuit that detects the frequency of the string variations, and an NXT brick with a program that sends a signal to a monitor to tighten or loosen the string so that its frequency matches a given frequency, "TuningBot" was both ambitious and sophisticated. Ultimately the robot used its sensor to tune a string to a certain frequency, and that was music to everyone's ears, especially those of the students who labored to construct and program it.

The final demonstration featured "Lil' B the Bridge Bot," crafted by juniors Elliot Wainwright and Evan Hagedorn to help solve a practical engineering problem by testing the structural integrity of bridges. "Lil' B" measured the strength of a bridge by tapping the surface with a force-sensing resistor, and using a simple voltage divider to compare to a desired force. When the bridge was structurally unsound, the robot would alert the user, then cleverly deploy a temporary bridge over the affected area and cross over it.

All in all, the robots and their alter egos — the students — did their job admirably, but the biggest applause was reserved for Dr. Garg when it was announced that this would be her final teaching assignment, bringing to a close a distinguished career that spanned more than 25 years as both a professor and an administrator.