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

This is the second 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. 
  
DAY 3 – June 2 
The On-Road Energy Use Event was completed successfully.  The vehicle – driven by Eric Diamond, ECE senior – behaved as intended, and having driven it myself for a few miles I must say that the engine automatic start-stop feature coupled with the rear axle electric launch must have saved a fair amount of fuel.  Anyway, the unofficial refueling (in which the tank is removed from the vehicle and weighed) amounted to approximately two gallons for a test that covered over 70 miles of stop and go traffic, highway driving, and which also included some hilly terrain.  We will not know the official figure until the end of the competition, but our impression is that we improved significantly over last year’s fuel consumption figures, which were already 30% better than the production Equinox. 
After lunch (graciously hosted by GM in their cafeteria), the teams moved to “Black Lake”, the vehicle dynamics testing area, where team pictures were taken and the Vehicle Dynamics Handling Event took place.  This event is an autocross contest, in which each vehicle has three attempts at completing a winding course marked by pylons (cones).  Penalties are given for knocking down pylons and for not stopping in the designated area at the end of the run.  Each team could take advantage of a professional driver supplied by GM for one of the tree runs.  A GM pro took out a production Equinox recording a time of just under 65 seconds.  A second driver followed in a Corvette Z06 recording a time of 56 s.  That was fun to watch!  At the end of the trial, three teams were very closed to one another: Wisconsin, Mississippi State and Ohio State, with times of approximately 65, 66 and 67 seconds, respectively.  The next best was about 70 seconds. Needless to say, the best time was recorded by the GM driver in each case.  However, OSU’s “Squealing” John Neal, ECE senior, had a personal best time of 70 seconds, by far the fastest time recorded by any student! 
One more time, the OSU vehicle has demonstrated performance very close to that of the production vehicle. At this time the three teams mentioned above are the ones that are consistently outperforming the others. It is a long way to go yet, but so far the Buckeyes are looking good! 
One note for the technically inclined.  All three of the top performing vehicles have similar architectures, employing an advanced Diesel engine (all Opel 1.9 JTDs) and a dual electric architecture.  Hmm… Maybe there is something to be said about this powertrain configuration. 
  
DAY 4 – June 3 
As I am writing these notes, the team is in line to participate in the On-Road Emission testing Event.  GM has chosen to use a Semtech in-vehicle gas analyzer system for this test, so emissions will be measured during a real-world driving cycle.  We are now waiting to have the system connected to our vehicle exhaust system, and should complete the event this morning (it’s 8:15 local time). This is a very important event with a score equal to the energy use event, and is a particularly difficult test for all Diesel equipped teams because of the NOX emissions, which tend to be the biggest hurdle for a Diesel engine.  Since last year the team has refined the engine control strategy, using the electrical powertrain to reduce the load on the engine (and hence the NOX emissions), improving the Exhaust Gas Recirculation (EGR) strategy, and eliminating idle emissions through the start-stop system. Further, the team has also implemented a dual lean NOX trap exhaust system.  We hope to see significantly reduced emissions figures with respect to last year. 
If all goes well, we should also be able to attempt the rest of the dynamic events today.  These include the AVL Drive Quality Event, in which vehicle drivability is measured, and the Trailer Towing Performance Event, which include a 16% grade and a 2500-lb trailer.  The last dynamic event is the Dynamic Consumer Acceptability.  More on all these in the next report.  Meanwhile, let’s have a cheer for our high-performance, energy-efficient and low-emissions Buckeyes!  
  
Stay tuned for updates, and GO BUCKS! 
 
Giorgio Rizzoni 

This is the third 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. 
  
DAY 4 – June 3

Well, the on-road emissions test was completed uneventfully.  We will know the outcome in a few days.  Immediately after the emissions event, the CXBuckeyes were off to the AVL Drive Quality Event.  This event is objectively evaluate the driving quality of the vehicle through a set of driving modes that include acceleration, cruising and braking.  Vehicle longitudinal acceleration and perceived acceleration in the cabin are measured and used to assess the vehicle “drivability”.  This event was a real success for our team.  The electric launch, engine start-stop and torque belinding features worked seamlessly, and we received repeated compliments on the vehicle drivability from GM and AVL engineers.  While the final scoring has not been decided yet, the consensus was that our vehicle was rated the best of the ones that have completed the event.

Next in line, after another fine GM lunch (I do not believe that GM staff experience the same quality on an average day…) was the Trailer Towing Performance Event.  The main feature is to demonstrate the ability to tow a 2,500-lb load over a 16% grade at reasonable speed.  Each team is to repeat the test three times.  Kris Sevel had started the third loop when a violent thunderstorm hit the proving ground, and the organizers decided to abort the attempt and reschedule the trial. Kris had already beaten the fastest time up the hill (held by Wisconsin until then) by over 1.5 seconds (19.5 vs. 21).  We will have to repeat the entire event when the roads have dried up some. Oh well. In all fairness, given that rivers of water were pouring down the 16% grade, this was probably the right decision.

The rain did not seem to create any problems with respect to the Dynamic Consumer Acceptability Event, so the vehicle moved on to this event, the only dynamic test left.  The objective of this test is to assess and score, subjectively, the vehicle noise, vibration and harshness, and ride and handling.  This test is conducted by two independent (GM) evaluators.  Being a subjective test, it is hard to tell how the vehicle is judged – we think it drives like a production Equinox! 

One note about Saturday evening – In my second report I neglected to mention that at the completion of the Vehicle Dynamics Handling Event, GM hosted an unusual event they called the Student Driving Experience.  Thankfully, faculty were also invited!  MPG made available 51 GM vehicle in current production, plus a few that will be hitting the showrooms next model year.  The teams spent the next two-plus hours test driving a variety of GM products including five different hybrid vehicles (Aura, Malibu, new and old Saturn Vue, Tahoe – with the 2-mode hybrid system to be introduced in the fall).  It was a very successful experience, capped by a very nice barbecue by the side of the test track.