This is the first of a series of reports that will be issued from the ChallengeX competition to relate the progress of our ChallengeX Buckeyes at the General Motors Milford Proving Ground (MPG). Please feel free to distribute this report as you see fit.
ChallengeX is a four-year competition sponsored by the US Department of Energy, General Motors Corporations, and several other organizations and companies from the US and Canada.
17 American and Canadian universities now entering their second year in the race to convert a gasoline-based 2005 Chevrolet Equinox SUV into a hybrid vehicle maximizing fuel economy, reducing emissions ratings and maintaining the safety and performance of the original vehicle.
The Ohio State team's architecture involves replacing the stock engine and transmission with a GM 1.9 liter turbodiesel and an automatic 6-speed transmission. Coupled to the engine is a belted starter/alternator (a small motor); further, the rear axle is powered by a 50kW AC induction drive. The electrical systems are powered by a 300-V NiMH battery pack.
The team has had access to some of the most advanced tools and design philosophies in industry, and must create a fusion of expertise in:
mechanical engineering
electrical and electronics engineering
control and systems engineering
engine control and exhaust aftertreatment
management, finance, and public relations.
DAY 1 – May 31
The team, led by Dr. Shawn Midlam-Mohler, arrived at the competition to find that the vehicle – shipped separately – was ready to pass final technical inspection. The team passed technical inspection on the same day without any difficulties. After passing tech inspection the team started to prepare for qualifying, including braking and dynamic safety evaluation – tests aimed at determining the safe operation of the vehicle. Unfortunately, the engine refused to start. The day ended at 8pm without any resolution of the problem.
DAY 2 – June 1
On the morning of the second day the team focused on troubleshooting the source of the problem; after independent testing determined that the fuel pump and injection system operated correctly, it was determined that the source of the problem was a tap made in to the crank position sensor to provide a feedforward system for the belted starter-alternator active vibration damping system was not viewed very favorably by the engine control unit. As soon as the signal splice was eliminated the engine started without any problem, and the team could proceed to qualifying and to the acceleration test. Qualifying: braking and dynamic safety evaluation was completed without any problems, and the acceleration test was especially successful, recoding the fastest ever 0-60 for the vehicle: 9.95s, slightly better than the published 0-60 time for a stock Equinox. Unfortunately, at the end of the acceleration run, one of the half shafts on the front axle sheared off. We can thank the aggressive driving of "hot shot" Eric Schacht, ECE undergraduate, for the outstanding acceleration performance...
The half shafts had been friction welded from two parts, one from the original Equinox, the other from an Opel Vectra. The vehicle had to be towed back to the pits, but the acceleration event was successfully completed. The support staff of the GM MPG took charge of the needed repairs immediately, and the broken half shaft was in the hands of the welding shop by 11AM.
Just before lunch, Rick Wagoner, President and CEO of General Motors, paid a visit to the teams, and gave a brief but inspirational speech. He then answered various questions from the students and joined the team captains (including our own Kris Sevel) for lunch. We were told that he was having so much fun he ended up being late for all his engagements the rest of the day...
Well, the lunch break was what it took for the GM welding wizards to return a fully functional half shaft. By 4:30 the vehicle was back in one piece, and heading out for the next challenges; the traction control and noise events.
The Traction Control Event measures vehicle traction on a low coefficient of friction surface by accelerating the vehicle from a complete stop and best accelerating through a straight line while maintaining vehicle control. The CXBuckeyes recorded a very low time (second lowest at that time, but more vehicles need to complete the test).
The Noise Event involves measuring exterior noise using the SAE J-1470 test, and interior noise using a binaural measuring system inside the vehicle. The OSU vehicle had excellent noise characteristics, comparable to those of a gasoline engine powered vehicle, in part thanks to the extent of electric launch on start up, to the excellent sound insulation package, and to Kris Sevel's active noise and vibration cancellation system based on the belted started alternator. Kris recently defended his M.S. Thesis on this subject, and has already published a couple of papers on his work.
That pretty much wrapped the day, and the team enjoyed a quiet dinner in Milford before retiring for the night.
DAY 3 – June 2
This morning the team divided into two groups. One group went to the MPG to continue with the dynamic events. The other half stayed at the hotel to work on various presentations that will be delivered on Tuesday and Wednesday.
At the time of writing this note, the vehicle has been on the road completing the On-Road Energy Use Event. This event consists of over two hours of driving under a variety of conditions simulating real-world driving. The introduction of the automatic engine start-stop system and the fine tuning of the energy management strategy should result in improvements over last year's energy consumption figures. If the test is completed successfully,
OSU will be one of only two or three teams that have completed these many events. West Virginia and Tennessee also left with OSU at 8 this morning to complete the event, but both returned to the pits due to technical problems.If this event is successfully completed, there may be time to complete another event in the afternoon, possibly on-road emissions testing.
Stay tuned for updates, and GO BUCKS!
Giorgio Rizzoni
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Pete Miller - Fundraising Chair
The Ohio State University
Buckeye Bullet 2
Student Land Speed Racing Team
www.BuckeyeBullet.com www.BuckeyeBullet.Blogspot.com(614) 284-8563 anytime