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Abstract |
Look-ahead Control of Heavy Trucks utilizing Road Topography
The power to mass ratio of a heavy truck causes even moderate
slopes to have a significant influence on the motion. The velocity
will inevitable vary within an interval that is primarily determined
by the ratio and the road topography. If further variations are
actuated by a controller, there is a potential to lower the fuel
consumption by taking the upcoming topography into account. This
possibility is explored through theoretical and simulation studies as
well as experiments in this work. Look-ahead control is a predictive strategy that repeatedly solves
an optimization problem online by means of a tailored dynamic
programming algorithm. The scenario in this work is a drive mission
for a heavy diesel truck where the route is known. It is assumed that
there is road data on-board and that the current heading is known. A
look-ahead controller is then developed to minimize fuel consumption
and trip time. The look-ahead control is realized and evaluated in a demonstrator
vehicle and further studied in simulations. In the prototype
demonstration, information about the road slope ahead is extracted
from an on-board database in combination with a GPS unit. The
algorithm calculates the optimal velocity trajectory online and feeds
the conventional cruise controller with new set points. The results
from the experiments and simulations confirm that look-ahead control
reduces the fuel consumption without increasing the travel time. Also,
the number of gear shifts is reduced. Drivers and passengers that have
participated in tests and demonstrations have perceived the vehicle
behavior as comfortable and natural.
Erik Hellström
2007
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Senast uppdaterad: 2021-11-10
