Student-built robots make leaps and bounds

While most engineering students spent reading period cramming for exams, the students in MAE 321 were busy building search and rescue robots.

Students in the Mechanical and Aerospace Engineering class logged many hours of research and labor to produce the robots Canyonero,Johnny 5, The Stinky, Squirrel Brand, Walter and Wangdoodlerest. Students worked in groups of five to eight.

The students completed two projects during the semester. For the first five weeks of the course, they constructed cranes. Then from fall break until Deans' Date, they worked on the robots. Putting together the complex robots made the first project look simple in comparison.

"We decided that after working in the machine shop [on the robots] for as long as we did, we had the skills to do a crane project in about 1 hour, as opposed to the original 12 hours it took to build the first one," Dave Follette '04 said in an email.

The students first created a drivable chassis, the frame that supported the body and motor of their robots, which was due before Christmas break. Course instructors judged the robots on how quickly they completed each of four stages as well as how many penalties they incurred during each stage.

The first stage was an obstacle course of cones and bumps through which the teams navigated their robots via remote control. Judges gave penalties for bumping into side walls or pylons. The second stage included scaling a one-foot wall and landing upright. Next was a straight 100-foot drag race to evaluate the ratio of power to weight.

Finally, the robots had to complete an autonomous portion, involving making a 180-degree turn, tracking a flashlight and traversing a 100-foot corridor while stopping within an 8-by-8 foot goal zone. Teams incurred penalties if their robot failed to stop, if it did not end within the goal zone or if it hit the walls of the corridor.

In addition, each group was required to write a report describing its robot. The reports "didn't directly affect the robot scoring, but they did affect our grade and [were] huge undertakings, in the neighborhood of 30 pages of normal text, plus several appendices and lots of figures," said Leah Crider '04, a member of the winning team.

Each of the six groups had unique designs for their robots. One group, comprising Follette, Naomi Chow '04, Johanna Kleingeld '04, Mati Chessin '04, Josh Girvin '04, John Swigart '04 and Hugh Strange '04 included several components in the design of their robot, named "Wangdoodlerest."

"It had two sets of powered wheels, so it drove around like a tank," Follette said. It was radio-controlled except for the autonomous section which used three light sensors and a program the students wrote, permitting the robot to track the light and drive itself towards a flashlight at the end of he hallway.

"Two of these [sensors] were used to adjust the position, while the third was used to determine when to turn around 180 degrees and also to stop," Swigart said in an email.

For the wall traversal, Wangdoodlerest utilized two innovative mechanisms. The "SuperScissor," was used to push the robot off the ground like a car jack, but in an arc, until it was high enough over the wall. The powered arms were used for balance and to flip the robot over so that it could repeat the wall traversal again if necessary. In this way, the design was repeatable. "Our robot could successively climb over several walls with complete reliability," said Chow.

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The SuperScissor was innovative enough to grab the attention of a patent lawyer at the robot presentation who thought the design had patent potential, Chessin said. The group that built The Stinky consisted of Chris Carr '04, Lizzy Louis '04, Cory Jerch '04, Matt Antony '04, Lindsay Turk '04, Charlie Louden '04 and Yusuke Okabayashi. The Stinky used a large fireman's ladder telescoping arm to pull itself over a wall and a second rotating butterfly-like arm to raise.

A shortage of computers with the needed software and a machine shop under-equipped made the project somewhat more difficult, Louis said. However, she noted that it still "was good, real-life, applicable experience."

The group whose robot scored the most points included Crider, Randy Bly '04, Patrick Coogan '04, Nate Lindell '03, Will Moore '04, Adrian Mullings '04 and Orion Crisafulli '03. The main features of their robot, "Walter," were a grappling hook to traverse the wall on the obstacle course and a different gear ratio than the other robots, which made it faster in the drag race.

Colin Ligon '04, Tyler Mincey '04, Paul VanDuyne '04, Aaron Ellerbee '04 and Brendan Davanagh '04 worked together to create the robot "Johnny 5," so named because "it had tank treads and pretty much looked just like the star of Short Circuit," Ligon said in an email.

The creators of "Squirrel Brand" kept division of labor in mind. Team members designed the robot frame and drive system to be completed independently of the arm, allowing the group to divide the tasks among all members.

"Some people worked on power management (deciding how many batteries to use and what sort of motors we would need); some worked on programming the robot for the autonomous portion; some built the frame," Thomas said in an email. "In the last day before the competition, we assembled and mounted the arm and began testing the autonomous programs. As always, there was not enough time."

This pressure of a rapidly-approaching deadline was felt by all the groups.

"The entire week leading up to Deans' Date, we spent all our time on the robot. Literally," said Chow.

Follette added, "All other classes (and sleep), didn't get very much attention, since we spent upward of 18h/day on the robot."

"I only got a total of 13 hours of sleep in the 109 hours leading up to the competition," said Swigart.

Similarly, Squirrel Brand builders spent 8-12 hours a day in the shop.

Ligon summed up the experience saying he got "no sleep, desperately trying to get the robot done without wholly abandoning the 11 million projects and exams in other classes."

When Deans' Date arrived, "there was controversy surrounding the grading of the completed robots," said Carr. Only three of the six robots completed all four stages of the evaluation. However, these three robots did not necessarily place first, second, and third. "After a lengthy volley of emails between several students and the professor of the class, the performance scores were adjusted, but no significant changes were made," Carr said.

Despite the grading controversy, the students seemed to grow and learn from the challenge of building their robots. "All in all, it was very intense and very challenging, but we were really happy with the result," said Follette.