On predicting fuel consumption and productivity of
wheel loaders

Abstract: Low fuel consumption is becoming more and more important as a selling
argument as fuel prices keeps rising. To be able to better show their
advantage in this area, Volvo Wheel Loader need to develop the selling tool
SiteSim in terms of fuel consumption predictions. This means modelling the
actual work done by the wheel loaders.

A good physical model would produce the results wanted. This modelling is
however very difficult due to the interaction between the hydraulic system
and the drive train. To overcome this problem, a method of splitting up the
work cycles of a wheel loader into phases has been developed. The phases are
defined by a specific type of work, for example filling bucket or reversing
from bank. This reduces the effecting parameters and makes physical modelling
possible in some phases. It also makes statistical modelling easier and more
exact.

The statistical models yields good results if the user is experienced in the
work the simulated wheel loader are to perform. The physical models produce
results with 10-20% lower fuel consumption than tested value. Better models
of energy losses in drive train would probably correct some of these errors.