Roy Ovesen:

Roy Ovesen:

I've added some features to the PID controller:

Ability to set desired sampling interval in seconds. Use <Ts> under <config>
to set the desired sampling interval of the PID controller.

Example:
<config>
     <Ts>0.1</Ts>        <!-- desired sampling interval -->
     <Kp>-0.05</Kp>        <!-- proportional gain -->
     <beta>1.0</beta>    <!-- input value weighing factor -->
     ...
     ...
</config>

Ts defaults to 0.0, so if you don't set it it samples at the highest possible
frequency.

Add an offset to the input variables (input and reference).
Example:
    <reference>
      <prop>/controls/flight/elevator</prop>
      <scale>-1.5</scale>
      <offset>1.0</offset>
    </reference>

Note that <scale> has higher precedence than <offset>, regardless of the order
that they appear in the config file.