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A3-PROJECTS
A3 | A3 – Austrian Advanced Automotive Technology | A3 – 1 st Call (2002)
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Intelligent electro-mechanical auxiliary units for motor vehicles
The aim of the project was to conduct a detailed investigation into and to optimise the
efficiency of the auxiliary units and the corresponding auxiliary drives on modern motor
vehicles.
One of the main project objectives was to create a progressive simulation environment
for vehicle and engine manufacturers for evaluating different drive system concepts
and also for reducing energy consumption in heavy goods vehicles.
A detailed digital simulation was developed in MatLab Simulink. Using this simulation,
it was possible to calculate the longitudinal dynamics of a motor vehicle, taking
account of the corresponding driving resistances such as air resistance, the specific
resistance on an inclined track, curve resistance and rolling friction resistance. The
simulation included the entire powertrain with relevant primary and secondary auxiliary
units such as the water pump and the oil pump, together with the air-conditioning
compressor, the air compressor and the steering booster pump. Furthermore, a control
model of an electronic drive was implemented.
The simulator routine was fed with accurate real-world cycle data, taken from test
rides with a heavy goods vehicle. The measurements were taken with a very high
sampling rate, and also included fuel consumption. Detailed characteristic diagrams of
the engine and the auxiliary units taken from test bench investigations have also been
used as input data. Comparing measured and calculated fuel consumption showed a
very good match when averaged over a range of driving distances, and a good match
when viewed in detail.
Strategies for controlling the auxiliary units were implemented in order to realise
efficiency improvements on the vehicle. The mechanical power of every individual
auxiliary unit was adjusted to the power demand, regardless of the speed of the
internal combustion engine. This meant that models for variable continuous drives for
the auxiliary units were implemented. The size and functionality of the auxiliary units
have not been changed. Using these optimised control methods, it has been calculated
that there will be a two per cent improvement in fuel consumption in a fully-loaded
vehicle.
Project management:
arsenal research GmbH
Project partners:
MAN Steyr AG, Vienna University of
Technology – Institute for Internal Combustion
Engines and Automotive Engineering, Graz
University of Technology – Institute of Electrical
Measurement Technology and Measured Signal
Processing
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