13.02.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

6 The optimiser: <strong>an</strong> evolutionary algorithm approach 56<br />

• Select the control values with respect to the last one applied to avoid jumps.<br />

• Prevent control outputs which exceed limits by replacing them with p<strong>an</strong>ic h<strong>an</strong>dlers,<br />

i.e. special outputs.<br />

A flowchart <strong>of</strong> the algorithm is found in Figure 6.3. The methods applied are<br />

described in detail in the next sections.<br />

����<br />

����������������<br />

���������<br />

������������<br />

�����������<br />

���������<br />

����������<br />

����<br />

������������<br />

�����<br />

������<br />

�������<br />

��������������<br />

����������������<br />

������������<br />

�������������<br />

��������<br />

�����������������������������������<br />

������������<br />

���������<br />

�������<br />

�������������<br />

�������<br />

����������<br />

�������� ��������� ����������<br />

���������� ��������<br />

����������������<br />

���������������<br />

���������<br />

����������<br />

����������<br />

���������������<br />

��������������<br />

����<br />

������������<br />

�����<br />

����������<br />

����������<br />

������������<br />

�������������<br />

�����������<br />

������������<br />

�����������<br />

�����������<br />

�������������<br />

����������<br />

���<br />

����<br />

������������<br />

��������<br />

Figure 6.3: Flowchart <strong>of</strong> the incremental multi-objective evolutionary algorithm.<br />

At the start <strong>of</strong> each time-step the system states (temperatures, humidity <strong>an</strong>d other<br />

sensor values) are updated. They are then used in the system prediction. The population<br />

is built up by the elite from the last run <strong>an</strong>d a const<strong>an</strong>t base population. The remaining<br />

individuals <strong>for</strong> the population are r<strong>an</strong>domly chosen from the design space. Using the<br />

system model, the future states are predicted <strong>for</strong> each individual. Based on these the<br />

objectives are evaluated <strong>an</strong>d the results stored. In the following step the population is<br />

compared using the limits <strong>an</strong>d priorities r<strong>an</strong>king scheme.<br />

The r<strong>an</strong>king is decisive <strong>for</strong> the selection as parent. The parent couples are recom-<br />

bined <strong>an</strong>d the resulting <strong>of</strong>fspring mutated. The objectives are evaluated <strong>for</strong> the children<br />

<strong>an</strong>d a r<strong>an</strong>king together with the parent generation is conducted. Finally this r<strong>an</strong>ked list<br />

��

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!