ec145/Systems/propulsion-rules.xml

<?xml version="1.0"?>

<PropertyList>
  
<!-- 
    Propulsion with turbines for YASIM helicopters.

    Implements property rules and a governor PID controller that is configured by the Nasal
    propulsion.nas script.

    To use this you must load propulsion.nas from the aircraft-set file. 
    This file propulsion-rules.xml must reside in the aircrafts Systems folder and must be 
    included via the aircraft-set file in the property tree as autopilot.

-->

    <!-- engine 1 freewheel -->
    
    <filter>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>0</reference>

        <input> <!-- if rotor running n2 diff -->
            <condition>
                <greater-than>
                    <property>rotors/main/rpm-pct</property>
                    <value>0.01</value>
                </greater-than>
            </condition>
            
            <expression>
            <dif>
                <property>engines/engine[0]/n2-pct</property>
                <property>rotors/main/rpm-pct</property>
            </dif>
            </expression>
        </input>
        
        
        <input> <!-- if rotor not running set to 0 -->
            <condition>
                <less-than>
                    <property>rotors/main/rpm-pct</property>
                    <value>0.01</value>
                </less-than>
            </condition>
            <value>0.0</value>
        </input>

        <output>
            <property>controls/rotor/gov/n2-diff[0]</property>
        </output>    
        
    </filter>

    <filter>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>0</reference>

        <input>
            <expression>
            <table>
                <property>controls/rotor/gov/n2-diff[0]</property>
                <entry><ind>-100.0</ind><dep>1.0</dep></entry>
                <entry><ind>-1.0</ind><dep>1.0</dep></entry>
                <entry><ind>0.0</ind><dep>0.0</dep></entry>
                <entry><ind>100.0</ind><dep>0.0</dep></entry>
            </table>
            </expression>        
        </input>

        <output>
            <property>engines/engine[0]/freewheel</property>
        </output>    
        
    </filter>


    <!-- engine 2 freewheel -->
    
    <filter>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>0</reference>

        <input> <!-- if rotor running n2 diff -->
            <condition>
                <greater-than>
                    <property>rotors/main/rpm-pct</property>
                    <value>0.01</value>
                </greater-than>
            </condition>
            
            <expression>
            <dif>
                <property>engines/engine[1]/n2-pct</property>
                <property>rotors/main/rpm-pct</property>
            </dif>
            </expression>
        </input>
        
        
        <input> <!-- if rotor not running set to 0 -->
            <condition>
                <less-than>
                    <property>rotors/main/rpm-pct</property>
                    <value>0.01</value>
                </less-than>
            </condition>
            <value>0.0</value>
        </input>

        <output>
            <property>controls/rotor/gov/n2-diff[1]</property>
        </output>    
        
    </filter>

    <filter>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>0</reference>

        <input>
            <expression>
            <table>
                <property>controls/rotor/gov/n2-diff[1]</property>
                <entry><ind>-100.0</ind><dep>1.0</dep></entry>
                <entry><ind>-1.0</ind><dep>1.0</dep></entry>
                <entry><ind>0.0</ind><dep>0.0</dep></entry>
                <entry><ind>100.0</ind><dep>0.0</dep></entry>
            </table>
            </expression>        
        </input>

        <output>
            <property>engines/engine[1]/freewheel</property>
        </output>    
        
    </filter>
    
    <!-- governor target rpm difference -->
    
    <filter>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>controls/rotor/gov/reltarget-internal</reference>
        <input>
          <expression>
           <prod>
                <property>rotors/main/rpm-pct</property>
                <value>0.01</value>
            </prod>
          </expression>
        </input>
        <output>
            <property>controls/rotor/gov/reltarget-diff</property>
        </output>    
    </filter>

    <!--unused : alternatively to using YASIMs internal PD for a gonernor, this PID has been used 

    <pid-controller>
        <name>Rotor Governor</name>
        <debug>false</debug>
        <input>
            <property>controls/rotor/gov/reltarget-diff</property>
        </input>
        <reference>
            <value>0.0</value>
        </reference>
        <output>
            <property>controls/rotor/gov/maxreltorque</property>
        </output>
        <config>
            <Kp>40</Kp>        
            <beta>1.0</beta>     
            <gamma>0.0</gamma>   
            <alpha>0.1</alpha>   
                                
            <Ti>1.0</Ti>        
            <Td>0.001</Td>    
            <u_min>0.0</u_min> 
            <u_max>1.2</u_max>
        </config>
    </pid-controller>

    <filter>
        <name>Governor Power Limiter</name>
        <type>gain</type>
        <gain>1.0</gain>
        <reference>0</reference>
        <input>
           <condition>
            <greater-than>
               <property>controls/rotor/gov/maxreltorque</property>
               <property>controls/rotor/gov/maxrelpower</property>
            </greater-than>
           </condition>
           <property>controls/rotor/gov/maxrelpower</property>
        </input>
        
        <input>
                <property>controls/rotor/gov/maxreltorque</property>
        </input>
        
        <output>
           <property>controls/rotor/maxreltorque</property>
        </output>    
        
    </filter>
    -->    
    
</PropertyList>