Design of an Automatic Control Algorithm for Energy-Efficient ...

1 Introduction
Energy consumption takes a growing importance in industry and consumer products, as a
risk for the world climate, but also as a cost factor and selling point. The car industry is
on the run for the “green” car, driven by growing international standards and restrictions
for emissions and consumers demands. On the horizon a new type, the electric car, can
be seen.
The climatisation of these vehicles becomes a difficult task. On the one hand the
power consumption should decrease, on the other hand a replacement for the lower “waste-
heat” of motors (especially when using electric ones) needs to be available. In order to
solve this dilemma, car climatisation becomes a field of innovative concepts offering new
possibilities of (automatic) climate control.
1.1 A brief history of car climate control
When the first cars got faster they needed a closed car body. This enclosed space had
to be ventilated in order to provide the passengers with fresh air. The first ventilation
systems - windows that could be opened - were controlled by hand. The heaters that
became standard in the fifties [1] were operated by the driver as well via a turning knob
or other elements.
This did not change even when the first air conditioning providing cooling and
dehumidification (without the option of air humidification) was introduced into the mass
market (first 1954). The mechanics behind the knobs were changed to potentiometers and
motors from the 1970s onward (seen in Figure 1.1), but today the “thermal control loop”
is still often closed by the human in the car: The driver adjusts the inlet-air settings in
order to achieve a comfortable climate.