University of Michigan's Sunrayce Strategy Is Enhanced by PCs Linked to Satellites
No most people, rain in the morning means a slight nuisance and, at most, an extended commute. Fortunately, their vehicles power right along, sipping fuel much like their occupants sip their morning coffee. To the participants of the bi-annual solar car Sunrayce, however, rain in the morning, or even clouds, could spell disaster. Without the sun to charge the cars' batteries, the entire nation-spanning race can come to a grinding halt. Much like ancient sun worshippers, the race's participants revere, praise, curse and talk to the sun, hoping for just a few more days, or even hours, of sunlight. Into this atmosphere of total weather dependence stepped University of Michigan's Solar Car Team and took the checkered flag for the first two races ('90 and '93). They might have repeated their victory this past year ('95) but were experiencing some teething problems with their solar car and withdrew due to safety concerns. How can a team dominate in an event that didn't even exist prior to 1990? Steve McGillivary, Solar Car Team Design Director, attributes their success to innovation and dedication. Technical Innovation Like all the universities participating in Sunrayce, University of Michigan devises unique solutions to the mechanical, technical and logistical problems of traveling 1,100 miles over seven days in a vehicle relying solely on the whims of the weather. The Solar Car Team used a Dell Latitude XP i486 100MHZ Dual-Scan color-portable to perform various testing and diagnostic functions, including interfacing with a Fluke Hydra Logger data acquisition system to test and optimize the car's solar array. The laptop helped the team find bad cells in the array and correct them, giving the team an array capable of producing over 1,400 watts peak power. While racing, the laptop was used to monitor vehicle information telemetered from the race car; the color display produced clear and immediately recognizable graphs of information such as the car's speed, battery voltage, motor temperature and throttle position. The laptop also had pre-loaded course information, enabling the race strategists to give precise instructions to the race car drivers. Real-Time Satellite Info Crucial to the team's race strategy is the ability to forecast the weather for the next 24 hours. To this end the team used two Dell 590 XL 90MHZ Pentium computers hooked up to satellite antennas that downloaded information directly from weather satellites. Data was also retrieved through cellular modems from Weather Service International (WSI). This weather data was then fed into custom-written weather modeling software. "If we know the weather we can decide whether we should run fast, passing other cars or building a lead on them, or run slow and conserve our energy." The decision to run fast or slow in an electric-powered vehicle is a major one, because the faster you go the faster the batteries drain. The nightmare of every team is to be stranded with no juice in the batteries and no sun to recharge them. With the weather forecasting ability the Dell machiness give to the University of Michigan, their race strategy has yet to fail. Unsurpassed Dedication Students (they prefer the term "team members" to employees) are in charge of design and development, engineering, manufacturing, public relations, fundraising and just about anything else that g'es along with building a car. The level of dedication of the team members is amazing. "We basically dedicate most of our lives for two years to this project," says McGillivary. "Sometimes we spend 24 hours a day with the car, even sleeping with it, in order to get it ready." Although the project is basically a volunteer project, students do receive class credit for much of their work. "This is experience you don't get anywhere else," says McGillivary. With students doing study and research in design, manufacturing, composites and all aspects of production, they leave the project ready to apply their knowledge to real-world applications. So the next time you grumble about a bit of rain in the morning, be thankful that your car d'esn't depend upon the sun as much as your mood.
This article originally appeared in the 12/01/1995 issue of THE Journal.