Log data will provide relevant driving cycles for hybrids

Monday, November 18, 2013

Lars NielsenLars Nielsen, Professor at Linköping University, runs the project and is supervisor of one of the doctoral students. Lars says that the use of driving cycles in the automotive industry is increasing, but that so far they have proved difficult to generate and have been criticized for not being adapted to the prerequisites of the actual customers. The use by scientists of data e.g. from gps devices opens up new opportunities for customizing cars and correcting any mistakes earlier in the production chain.

– Now we can make use of large amounts of logged data from actual vehicles and take into account factors such as country, season and climate, explains Lars Nielsen. Such systematical use of large amounts of data to produce driving cycles is new and almost untried.

Further opportunities for hybrid vehicles
For hybrid vehicles, access to log data provides further opportunities to test how the driveline can be utilized optimally. From the driving cycle, load curves can be extracted for the internal combustion engine as well as for individual hybrid components.

– There is not much previous knowledge about hybrid cars, explains Lars Nielsen. Therefore more studies are required before launching a hybrid car. Relevant driving cycles make it possible to study for example how the battery is affected or how the energy management is acting during various types of driving.

Looking for methodology for the use of log data
There are no established methods as yet for how the logged data should be used in the driving cycles. The research will include the question of what such methodologies could be like.

-We ask ourselves how one can describe a large database using statistical measures and then generate a driving cycle with the same statistical measures, says Lars Nielsen. We also want to investigate how long the cycle needs to be for all the relevant data to certainly be incorporated, and find out which characteristics must be included.

The researchers want to develop a number of cycles which are equivalent but not exactly the same, which in a characteristic way describes what the vehicle is undergoing. By comparing the cycles, their relevance may be assessed and erroneous conclusions avoided.

The project involves researchers from Chalmers and Linköping University, whereof two doctoral students.

Participants including the steering group:
Lars Nielsen, LiU
Jonas Sjöberg, Chalmers
Anders Grauers, Chalmers
Viktor Judez, Chalmers
Peter Nyberg , LiU
Sören Eriksson, VCC
Mattias Björkman, Scania
Sixten Berglund, AB Volvo

Text: Emilia Lundgren
Photo: Peter Modin