Xenith

Xenith was the most technically ambitious car in the project’s history. To begin, the vehicle was designed to fit in an extremely svelte aerobody. Xenith had the smallest frontal area of all of the cars at the 2011 World Solar Challenge. The team therefore had to make multiple innovations to accommodate this small aerobody profile. Xenith featured a very compact multi-link suspension which provided a degree of dampening while still fitting in the car’s small fairing. The rear suspension of Xenith incorporated a linear actuator controlled rear steering system. This allowed Xenith to make U-turns without the need for wide wheel fairings. More importantly, it allowed Xenith to “sail” or “crab” in the wind. If the car encountered cross-winds during the race, the driver could fix the rear wheel at an angle which allowed the car to point into the wind while driving.

Xenith’s electrical system was one of the most robust in the SSCP’s history. The team never had to stop for an electrical problem during the race. The car’s electronic sub-systems ran on ST Micro micro controllers. The team worked on a helmet mounted heads up display which ran on Gumstix embedded linux system. The battery pack’s BMS and BPS provided extremely accurate voltage and current readings and had a few safety features to prevent the same over draining that had destroyed previous battery packs.

Xenith’s telemetry system featured a handy user interface that allowed any wi-fi enabled device to stream packets wit all kinds of data ranging from the tire pressure to battery cell voltages.

The solar panel array that the team developed was the first known glass encapsulate array for a solar car. The team worked with Corning to source a special production of ultra-thin, ultra-strong glass. Encapsulating the panels in glass instead of a plastic or other polymer allowed for greater optical clarity and it further protected the panels from the debris in the outback. The team had the glass panels coated with an anti-reflective coating which further improved the efficiency of the panels.

Xenith’s list of “cool” features goes on and on, but the car’s shortcomings stemmed from inadequate testing. The team didn’t find a way to get wind tunnel testing before the race which meant that the team was unable to adequately optimize the car’s aero body. Many other aspects of the car were still being modified

without testing in the days and hours before the race. Last minute decisions to change tire models, to add wheel covers, and more weren’t tested thoroughly before the race and eventually posed problems for the team. During the race the team knew that the car wasn’t reaching it’s predicted efficiency and it became clear that the team should have implemented build freezes sooner in the build cycle and should have put more test miles on the car and the race team.