PID Without a PhD (2016) [pdf]
I am a little suprised that the author does not use a low-pass filter for the D part, for example 1&#x2F;(1+s Tf) and instead tells you to modify the hardware.<p>Sure, you need cut off the noise with hardware in respect to your Nyquist frequence but you can still have a lot of high frequency noise.
And it is not always possible to use hardware filters to get rid of the noise, for example if your are tracking an object with a camera and the x,y is your input to the pid. Ofcourse you can skip the D part.<p>What am I missing here?<p>I also find it more easy to use a reset based integrator anti-windup, where you specify your limits on your control signal instead of limiting the integrator.<p>Here is an diagram of what I usally do:<p><pre><code>          +--------+           +------+
   -y     |    1   |           |      |
 --------&gt;+ ------ +----------&gt;+ Kd*s +----+
          | 1+s*Tf |           |      |    |
          |        |           +------+    v
          +--------+   +----+            +-+-+       +-------+   
   e=r-y               |    |            |   |       |    __ |      u
 --------+------------&gt;+ Kp +-----------&gt;+ ∑ +---+--&gt;+ __&#x2F;   +---+---&gt;
         |             |    |            |   |   |   |       |   |
         |             +----+            +-+-+   |   +-------+   |
         |                                 ^     |               |
         |   +----+   +---+    +-----+     |     |     +---+     |
         |   |    |   |   |    |  1  |     |     |   - |   | +   |
         +--&gt;+ Ki +--&gt;+ ∑ +---&gt;+  -  +-----+     +----&gt;+ ∑ +&lt;----+
             |    |   |   |    |  s  |                 |   |
             +----+   +-+-+    +-----+                 +-+-+
                        ^                                |
                        |                                |
                        |      +----+                    |
                        |      |    |                    |
                        +------+ kt +&lt;-------------------+
                               |    |
                               +----+


</code></pre>
The kt gain will reduce the integrator when we have saturated output.<p>Does some one knows the pros and coins with the different anti-windup solutions?