In order to diminish their reliance on fossil fuels, many companies who depend on truckbased services have made supporting the development of hybrid engines a top priority.
One of these firms, FedEx Express, selected three companies to participate in its search for a hybrid electric Class 4 step-van to become its delivery truck in 2004. The goal was to design a vehicle that would increase fuel efficiency by 50% and reduce emissions by 90%.
The company eventually chosen for the job was Eaton Corporation, and that's where ME student Chan-Chiao (Joe) Lin comes into the picture.
Lin's relationship with Eaton began when Jason Liu, an Eaton engineer, attended the annual Automotive Research Center (ARC) conference last May, where Lin presented his research on control strategy development of hybrid vehicles. Liu realized that Lin's research fit their requirement for the FedEx project and offered Lin a summer internship with Eaton.
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As an intern at Eaton from July to September 2002, Lin was actively involved in the company's hybrid electric truck project.
The company's plan was to leverage its significant experience in automated mechanical transmissions to develop a parallel-type, "Direct Hybrid" system, incorporating an electric motor/generator located between the output of an automated clutch and the input to an Eaton® Fuller® AutoShift® transmission.
This architecture makes it possible to recover energy normally lost during braking and store the energy in batteries or other energy storage devices. Electric torque can be blended with engine torque to improve vehicle performance and to operate the engine in its most fuelefficient range for a given speed, or to operate the vehicle with electric power only.
Lin's primary responsibility was to help design an advanced algorithm for the control strategy of the prototype hybrid truck for further fuel economy improvement. The control strategy in hybrid vehicles is responsible for the power management and coordination of overall vehicle systems, including the internal combustion engine, electric motor, transmission, and battery.
"Since we have developed a methodology at the Automotive Research Center to design the control strategy for hybrid vehicles," said Lin, "the basic job for me at Eaton was to apply this design methodology to their prototype hybrid truck to see if the fuel economy could be further improved. This also offered a good opportunity to validate my approach on a real hybrid truck." Lin was also involved with developing the hybrid electric truck simulation tool, testing/modifying the control algorithm, and analyzing the real-time data collected from the truck. He credits his mentor Jason Liu, manager Richard Nellums, and colleague Matt Busdiecker, for providing outstanding support.
Naturally, the key question is: did the team's work achieve their goal? The improved prototype truck was delivered to FedEx Express for final testing in September 2002. The fuel economy of the new truck achieved 45% improvement (compared to the 50% target) over the baseline FedEx truck. The particulate matter (PM) and NOx emissions were reduced by 93% and 54%, respectively (compared to the targeted 90% reduction).
As a result, FedEx has formally announced its intention to use the technology developed by Eaton in its fleet. According to a May 20 press release, "FedEx Express has agreed to purchase twenty hybrid electric diesel delivery trucks using Eaton's innovative hybrid electric technology. Later this year and into early 2004, these twenty vehicles will begin operation in four yet-to-be-named U.S. cities.... This program has the potential to replace the company's 30,000 medium duty trucks over the next ten years."
Lin is a PhD student under the supervision of ME Professor Huei Peng and Electrical Engineering and Computer Science Professor Jessy W. Grizzle. He is also a graduate student research assistant in the ARC, where he researches power management in hybrid vehicles. Lin received his BS ME from National Tsing Hua University, Taiwan in 1995, and an MS ME from National Taiwan University, Taiwan in 1997.