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

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11 Matlab implementation<br />

The climate controller is integrated into the Matlab Simulink model <strong>for</strong> the MUTE car<br />

control. All time critical tasks like the driving functionality are done in this program<br />

running on the dSpace MicroAutoBox. The in- <strong>an</strong>d output specifications <strong>for</strong> the climate<br />

control block c<strong>an</strong> be seen in Appendix B.<br />

11.1 Model structure<br />

The sensor input values will first enter a block called input validator (in Figure 11.1<br />

yellow on the left side). The containing routines check, if the data is within the sensor<br />

limitations <strong>an</strong>d if the servo motors are working. The scaling <strong>of</strong> the values into the later<br />

assumed r<strong>an</strong>ges <strong>an</strong>d unit conversion are done as well. The servo motor positions are<br />

tr<strong>an</strong>sferred into percent <strong>of</strong> air flow trough them. The absolute humidity <strong>of</strong> the cabin <strong>an</strong>d<br />

the ambient air is calculated. Found errors <strong>an</strong>d the sensor values (or replacements) are<br />

the output.<br />

The model has three working modes: <strong>Automatic</strong>, m<strong>an</strong>ual <strong>an</strong>d <strong>of</strong>f. A logic (grey<br />

block on the left in Figure 11.1) decides which one <strong>of</strong> them is active. Disabling not used<br />

mode-blocks is done to safe computing time. The second grey block uses these activation<br />

signals to <strong>for</strong>ward the desired control signal to the output. If the controller is switched<br />

<strong>of</strong>f (at start-up or during shut-down) the <strong>of</strong>f-settings (cy<strong>an</strong>, at the bottom) are activated.<br />

F<strong>an</strong> <strong>an</strong>d heater are turned <strong>of</strong>f <strong>an</strong>d the air inlet flap brought to the full recirculation<br />

position. The automatic control in the upper cy<strong>an</strong> block becomes active if the controller<br />

is switched on <strong>an</strong>d the automatic or the precondition mode is chosen. Its structure will<br />

be described in Section 11.2. The activation <strong>of</strong> the m<strong>an</strong>ual mode permits the user to<br />

directly control the output temperature <strong>an</strong>d air flow as well as the outlet (foot/defrost).

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