<?xml version="1.0" encoding='utf-8'?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id="card1" title="PID controller - Page 7 - Wikipedia">
<p>
<a accesskey="1" href="page.php?w=PID_controller&amp;p=6">1.Previous</a><br />
<a accesskey="3" href="page.php?w=PID_controller&amp;p=8">3.Next</a>
</p>
<p>to apply accurate and optimal control. The block diagram on the right shows the principles of how these terms are generated and applied. It shows a PID controller, which continuously calculates an error value  as the difference between a desired <a href="page.php?w=Setpoint_%28control_system%29">setpoint</a>  and a measured <a href="page.php?w=process_variable">process variable</a> : , and applies a correction based on <a href="page.php?w=proportional_control">proportional</a>, <a href="page.php?w=integral">integral</a>, and <a href="page.php?w=derivative">derivative</a></p><p>
<a accesskey="1" href="page.php?w=PID_controller&amp;p=6">1.Previous</a><br />
<a accesskey="3" href="page.php?w=PID_controller&amp;p=8">3.Next</a>
</p>

<do type="prev" label="Search">
        <go href="search.wml"/>
</do>

</card>
</wml>
