CAR Researcher Selected for Fifteenth Annual International Scholar Research Exposition
Manfredi Villani, a research associate at CAR, has been selected to be a part of Ohio State’s fifteenth annual International Scholar Research Exposition. The expo features research conducted by visiting scholars at The Ohio State University and was released online on March 18th.
Villani is one of 10 scholars selected for this year’s expo out of the roughly 1600 visiting scholars at the university. Usually, the expo is in-person and features the work of 30 scholars, but this year it was trimmed down and is being held online through a series of three-minute long YouTube videos because of the COVID-19 pandemic.
Villani’s research, the CERC Truck project, is about developing hybrid electric delivery trucks. Given the increased number of packages being delivered during the COVID-19 pandemic, this has been a particularly timely research topic.
“There’s been a big growth in E-commerce, also because of the pandemic- in particular because of the pandemic, and so there are more and more of these trucks, and we thought it was a good idea to make these trucks more efficient and less polluting,” Villani said.
It might seem like this would be as simple as taking the normal setup for a hybrid car and putting it in a delivery truck, but there’s a lot more complexity to it than that, especially if you want to be as efficient as possible. Your standard passenger vehicle has to be able to operate in a wide variety of different scenarios, from driving on the highway to driving through cities, while delivery vehicles mostly drive very slowly and need to be prepared to stop and start very frequently, and often drive for over eight hours a day.
There is also the problem of how heavy the battery is, and how delivery vehicles need to be able to carry as many heavy packages as possible for maximum efficiency. This is also why making purely electric powered delivery vehicles would be very difficult, and purely electric vehicles also come with the difficulty of requiring widespread recharging infrastructure, something hybrid vehicles can work without.
The trucks for this project use a type of hybrid power system called a plug-in series hybrid, which has a battery, an electric motor connected to the wheels, and an internal combustion engine that has no connection to the wheels but is instead used to generate additional energy for the vehicle. This type is the best for delivery vehicles because electric motors are much more efficient at starting and stopping than the internal combustion engine, and delivery vehicles do a lot of starting and stopping. On the other hand, the internal combustion engine runs the best when it can run for a long time without stopping, so by disconnecting the engine from the wheels, it can continue to power the battery even when the vehicle itself isn’t moving.
“In the series hybrid architecture that we’re considering, you are directly using the electric motor to power the wheels, so you will be always very efficient in using the energy to deliver power, because you’re using a directly electric machine. Then you will have also your engine, and you will operate the engine, since you’re not constrained by the operation of the vehicle, because the vehicle can start-stop any time, but the engine would stay operating at the possibly fixed high-efficiency point. So all the energy it uses, it will convert it into electricity for motor or the battery. That is what we call a ‘genset,’” Villani explained.
While in theory it’s possible to just have the genset kick in once the battery is completely depleted, that’s far from the most efficient way to power the vehicle. Instead, a computer called a supervisory controller inside the vehicle uses a series of rules to determine when the engine should be used to generate power, in order to slow the depletion of the battery. Determining when the genset and the battery should be used to maximize efficiency is called the “energy management strategy” and is the main focus of Villani’s research and expo presentation.
“It’s really, OK, you have the engine, you have the battery, which one are you going to use and when?” Villani explained.
Villani joined this project during its third year, having come to CAR as a visiting scholar after getting his bachelor’s degree, master’s degree and doctorate in mechanical engineering in Italy. He initially mostly worked on internal combustion engines, but CAR was doing so much research on electric and hybrid vehicles that he inevitably became involved in that kind of research, and he’s been an invaluable member of the team ever since.
“Dr. Villani’s role in Department of Energy-funded research programs related to reducing carbon emissions of commercial delivery vehicles has been instrumental. We are delighted that he will present the results of his work at the International Scholars Research Expo,” Giorgio Rizzoni, Villani’s faculty advisor, said.
Written by Laura Smith, CAR writing intern