by Dallas Downing
September marked the first time that RoboRacing attended evGrandPrix, an electric go kart racing competition hosted at the Indianapolis Motor Speedway by Purdue University. The team ended up taking 2nd Place in the Autonomous competition after a few intense days of testing, repairing, and racing.
The excitement was high. Everyone was looking forward to the competition since this was the first time the autonomous competition was held at evGrandPrix and the first time Rigatoni would be racing. The goal of the autonomous competition was to complete five laps of the go-kart circuit in the fastest time possible. A team was allowed three resets, where the kart could be replaced on the track following an e-stop or running off the track. Since the autonomous competition is so new, only three teams competed this year: Kennesaw State University, University of California San Diego/University of Maui, and RoboJackets. As more teams compete and the competition grows, the competition organizers expect to increase the minimum speed and have multiple karts race at the same time.
The competition was held the week of the 13th, with the final race taking place on the 17th. During the week of the competition, the team had a lot of preparations to make Rigatoni ready for a successful race. And “the team’s success would best be described as a high intensity roller coaster,” said project manager Sam Walters. In the two years since getting the go-kart chassis, this was the first time Rigatoni would drive on a proper circuit. Even with testing each sub-system before competition, the team knew they would need to make adjustments. On the first test day, Rigatoni was driven manually, but the software team noticed that the steering speed (how quickly wheels could change direction) was too slow for the planner to properly navigate turns, taking about 10 seconds to turn from left to right. This meant that Rigatoni would always overshoot the course’s many sharp turns. The team attempted to increase the steering motor’s speed to address this issue until disaster struck.
The steering motor burned out on Wednesday, so the team had to scramble to get Rigatoni working on Thursday. Thanks to some help from the Kennesaw team, they were able to come up with a replacement plan. Some members drove an hour to AndyMark’s headquarters to get a replacement motor and gearbox. The mechanical team got the new hardware incorporated into the steering axle while the electrical team worked to set up a new motor controller borrowed from Kennesaw. About half the team worked through the night getting everything working, including writing new firmware for the controller. Rigatoni was driving with manual control again a few hours before the main race. Using the remaining time, the software team was able to tune the path planner so Rigatoni could run without colliding into cones. Unfortunately, due to the long testing times, the batteries could not be fully charged before the race. Rigatoni could only make it about three-quarters of a lap before cutting out, but it was enough to guarantee second place.
Despite the challenges of competition, the team is optimistic about the coming year. “We are looking forward to revamping all of our systems,” says former mechanical lead Sam Morstein. The team learned a lot from the complications at competition and took inspiration from the competitors. Electrical lead Oankar Patil told us he’s somewhat frustrated with the old designs, but is also excited about the redesign opportunities for the new systems. “There’s going to be a lot of learning and improvement coming up for the team, that’s for sure,” he said. Design work on the next iteration, Rigatonii, has already begun. Software lead Nico Bartholomai is looking forward to “seeing [Rigatonii] really speed down the track” at the next competition when (hopefully) the team has more time for software testing.
Overall, the RoboRacing team is happy with what they accomplished. “We faced a lot of setbacks,” said Sam Walters, “but [we had] the drive to continue on against all odds.” No pun intended.