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

8 System and functionality integration 87
ample a constraint for the icing if a heat pump is employed. The icing can be integrated
into the energy consumption objective function by a modified efficiency of the heat pump.
However, to force de-icing above a certain limit in order to avoid damage to the com-
ponents, a separate constraint is advisable. Its limit can then be set without interfering
with the objectives while it is not exceeded.
8.2.1 Integration as boundaries
Some constraints vary, while others are fixed. These - as the flap passage and fan limits
- can be given as boundaries for the design space. Upper and lower limits for the other
design variables have to be set in order to limit the search area. A smaller design space
leads to faster results as unusable results are not considered.
These boundaries may be adapted by external signals or user settings in order to
force a different minimum or limit one variable. However, they may not depend on other
design variables or predicted states. In Table 8.1 an overview of the standard values is
given.
Table 8.1: Overview of the objectives and their corresponding parameters.
Design variable lower bound upper bound
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Boundaries for the de-icing switch and source selection are not required. Due to
their discrete nature only available values can be chosen.
8.2.2 Integration as objectives
All the constraints depending on design variables or predicted states have to be evaluated
for each individual. Therefore, they have to be implemented as special objective, as
described in Section 6.3.5. The functions, as shown above, return a value between -1 and