Robot Battles
Mechatronics Class Teaches Students the Culture of Automation
One day a year, the atria in Cornell University’s Duffield Hall morph from their usual role as a gathering spot for engineering study groups and coffee breaks into an arena for battling sumo-style robots. A midday visitor to Duffield on Friday, December 6, 2013, would have seen a space transformed. That day, tables and chairs were cleared away and hundreds of students gathered in a horseshoe-shaped group around a series of circular black arenas. Each arena was three feet in diameter and edged by a thick white line. Rather than the usual low hum of many simultaneous conversations, the visitor would have heard the clamor and roar of an audience very much invested in the outcome of pitched robot battles.
The combatants that day in Duffield were robots designed and built by students in Professor Hadas Kress-Gazit’s MAE 3780 class. There was also a robot guest of honor, built by engineers from the ASML corporation, who sponsored the class this year. This class, called Mechatronics, is one of the most popular offered by Cornell Engineering. In 2003, the first year Mechatronics was offered at Cornell, the class had an enrollment of 22 students. Ten years later, there were more than 160 students and nine teaching assistants.
“This is the course I always wanted to take as an undergraduate but didn’t get to take,” says course creator Professor Ephrahim Garcia of the Sibley School of Mechanical and Aerospace Engineering. “The course is designed to be a class in the actual creation of a controlled, mechanical, and electrical system, thus the name mechatronics. Every wire, every piece of solder is done by students.”
Adds Matt Ulinski, Master of Engineering program director at the Sibley School, “We wanted to create a class where students would learn the language and culture of automation—where they would gain an appreciation for the constraints and complexity of a problem.”
The course involves classwork, lab work, and independent work, as well as the final day of battles. Students are taken through all of the basics required to create their own automated systems. They study analog circuits, diodes, transistors, pulse width modulation, transduction, optical encoders, digital logic devices, microprocessors, and programming. Early on there is a series of labs that lays the groundwork students need to begin working in teams of three to create their own robots.
Students also learn to use the drill press and other equipment in the Emerson Machine Shop on campus. “In many undergraduate engineering programs it is possible to go four years without ever entering a machine shop,” says Garcia. “We want students here to have a chance to get their hands dirty and be creative.”
Says the Sibley School’s Kress-Gazit, “The students are given the constraints right away.Then they have lots of time in the lab to get creative. This is a fairly unusual class. The students really do amazing things.”
Here are some of the constraints Kress-Gazit mentioned, (as delineated in the Mechatronics Fall 2013 Final Project Packet): “Total robot mass not to exceed three pounds; ’bot dimensions are not to exceed eight inches by eight inches (width x length) at the beginning of the match—after the beginning of the match there are no size limitations on the ’bot; no water, liquid, chemical, biological, or nuclear weapons; any electrical, compressed gas, or otherwise potentially dangerous weapons must be approved by your TA.”
Kuen-Kuen Jeffery Sim ’14 MAE and his teammates won the competition in 2012. Sim says, “I really enjoyed the class and the opportunity to apply theoretical knowledge learned from classes to a hands-on project. Inspired by this class, I bought a few microcontrollers after my final exams were over and began working on some hobby-level electronics.”
Sim’s teammate Joshua Ren ’14 MAE spoke highly of the teaching assistants, “They were all patient and very willing to answer any questions we had,” says Ren. “I remember one time when I had to build a speed controller for a D.C. motor and I just couldn't get it right. The lab TA stayed significantly after the lab period was over to help me troubleshoot and figure out the problem.”
When Garcia and Ulinski developed the course, the robots were not battle-tested. Instead, they had to maneuver through a maze or tackle an obstacle course. After a few iterations, they settled on head-to-head battles as the culminating activity for the class. It quickly became clear to Garcia and Ulinski that they had hit upon magic.
“There is nothing more purifying than robotic combat,” jokes Garcia, pointing out something obvious to anyone watching the battles: “The machines don’t care who wins. But it seems to be human nature to project a human personality and human wants and desires onto the machines. We can’t help but root for one or the other.”
Some of the offensive capabilities built into those early robots included circular saw blades, a disposable camera flash mechanism converted into a robotic Taser, and a spatula attached to a large rat trap. The aggressive nature of some of the past modifications has been toned down over the years. The current list of rules includes a ban on untethered projectiles and objects capable of piercing the skin. Even with these rules, the competition is still spirited, with plenty of cheering, trash talk, and anthropomorphizing.
The most recent offering of MAE 3780 included a corporate twist. ASML, the world’s leading provider of lithography systems for the semiconductor industry, sponsored the class. Not only did the company donate an Arduino microcontroller platform to each of the 58 teams in the competition, but it also sent a team of engineers from ASML’s research, design, and manufacturing facility in Wilton, Conn.The engineers built their own robot to compete against the student robot champion. Ken Bogursky ’96 MAE, senior manager of mechanical development for ASML, led the team. “We develop state of the art mechatronic systems,” says Bogursky. “We need top-notch people and Cornell is one of the top engineering schools in the country.”
“First, we were just going to sponsor the class. It was a natural fit for us,” says Bogursky. “But then we decided it would be really fun to build our own robot and let it fight it out with the student ’bots.” The student teams had a series of milestones to reach each week, building upon what they were learning in class and labs. The team from ASML had no such structured progression to keep them on task. “And,” interjects Bogursky, “we didn’t get our kit until Thanksgiving!”
On the day of the tournament, the team from ASML paced nervously, talked with students, and checked out the competition. As Team ASML waited, Julian Whitman ’15 MAE and his teammate Benjamin Wu ’15 MAE watched their robot fight its way round by round to the student finals. “The competition went better than expected for us,” says Whitman. “We put a lot of work into the project, and rather than just trying to submit something functional, we went for gold. Hopes were low when we lost a match mid-competition, but we kept with it and managed to come back up to the top through the double-elimination losers’ bracket.”
By finishing first, Whitman’s robot won the right to face off against ASML’s robot, which was tall and narrow and looked a bit like a cross between a moon rover and a cargo container. Whitman’s robot had a low profile and two wing-like attachments that would drop to the sides when the robot was activated, becoming short flaps that protected it from the longer projections of some of the other robots. By the time the final battle took place in the Duffield atrium, there were hundreds of students at arena-level, standing on their tippy-toes to get a better view. Many more students, staff, and faculty lined the balconies overlooking the battlefield. Professor Kress-Gazit rang her brass gong, calling the rowdy crowd to silent attention. And then the final battle began.
As predicted by Ephrahim Garcia, it was clear that the crowd was taking sides. Many rooted for the plucky student machine that had fought its way out of the losers’ bracket and into the final. A smaller number were pulling for the ungainly ASML ’bot. The battle was epic. Neither robot was able to get the upper hand and push the other out of the ring. You could just tell that both machines wanted so badly to win. It was about pride and everything was on the line.
Or, more probably, it was not about pride at all.In fact, it was much more about traction and torque. As Garcia says, the machines don’t care. Though the crowd did care, and after a full three minutes of standoff punctuated by yells, cheers, insults, and encouragement, the match was declared a draw and both robots went home with their pride intact. Or, more probably, both robots were turned off and stowed away.
The machines don’t care. But the students, professors, TAs and ASML engineers do care, and it was clear that MAE 3780 is something they care about deeply.