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28 “They’ve done projects for many of the major automakers – for example, a reimagined BMW Mini – but in 2019, Clemson decided it would develop the blueprint for the IAC race vehicle,” he recounts. “That was really helpful, because the students were able to continually run and advance that programme from autumn 2019 through to spring 2021. “That freed us up to engage with industry leaders like Luminar and others, who would later become our most valued suppliers and whose hardware was essentially being designed into the form factor of a racecar by the Clemson University team.” The IL-15 was chosen because it has a format familiar to the crews and technicians at IMS, one that would draw eyes more readily than stock cars and sportscars. That encouraged Dallara to collaborate with Clemson, the former providing the chassis, aero and NVH work, and the latter providing expertise on designing, sourcing, integrating and planning powertrain modifications and autonomy-related sensors and computing. Dominic Coffey, design engineer at Dallara USA, says, “We started in April 2020 by exporting the CAD files of the IL-15 to Clemson’s people, including the monocoque, suspension, parts of the drivetrain we could supply, and aerodynamics models they could use. “Before long, we were having a weekly drivetrain development team meeting, a systems integration team meeting, an electronics meeting and so on with Clemson. We’d review their designs, and coach them on what might work or not – particularly in terms of installation and maintenance – to arrive at a solution that satisfied all the engineering requirements.” Autonomous racing requires very specific features that can be quite different from traditional motorsport, according to Dr Robert Prucka, who was faculty lead for Clemson’s role in the project and is Clemson University’s Kulwicki endowed professor in motorsport engineering. “We swapped the stock AER engine for one from Honda to better meet autonomous racing requirements,” he says. “One interesting target was that we wanted the vehicle to operate at the lowest ground speed possible, which is opposite to traditional motorsport engineering but critical to start mapping out a new track safely. “We built a function to replicate a low- speed ‘track walk’, just like professional drivers do before a race. The AV-21 has a minimum speed of around 19 mph without slipping the clutch, about 50% lower than what would have been achieved with the original engine. That forced us to investigate engines with low valve overlap without sacrificing a lot of peak power. “The engine also has to be incredibly reliable and tolerant of operating without pre-heated oil and coolant, since we knew there would be many quick stops and starts as teams developed their algorithms. We did not want an engineer to have to accompany each engine at all times, so the teams have maximum flexibility to develop their vehicles on their own timelines.” By autumn 2020, with some consultation along the way from AutonomouStuff, designs were being finalised and approved for manufacture so that first integrations of critical components such as the drive-by-wire systems from Schaeffler Paravan could be performed. “The bellhousing, which connects the gearbox to the engine, was another crucial manufacturing focus, and we designed it from scratch because we opted for a non-standard engine,” Coffey explains. “The IL-15 comes with an AER turbocharged four-cylinder engine, but we chose a Honda four-cylinder instead, so engine installation took a lot of attention.” Initial builds started in spring 2021, with the first fire-ups at Juncos Racing’s facility in Indianapolis in March, and the official AV-21s started to be assembled and finalised soon after. The first test run of the AV-21 took place around the end of March, with deeper, extended track tests taking place through to the autumn in the lead-up to the first official IAC race at IMS in the October. Meanwhile, the teams’ software development ran in parallel with Dallara’s and Clemson University’s vehicle development. They began programming using the initial AV-21s directly at the Juncos facility in May 2021, with algorithmic refinements continuing through the summer. This approach gave the teams the freedom to code and iterate with their own individual vehicles. Mitchell says, “Initially, some teams had to share vehicles, but that actually led to a lot of collaborative troubleshooting October/November 2022 | Uncrewed Systems Technology The cockpit holds most of the navigation sensors, with two GNSS antennas on a mast and two more on the sidepods, with the engine behind