PDDesign:

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   Design a PD controller of the form

   x = x + ax + bu
   y = cx + du

   If no outputs are requested then Bode plots for the controller will
   be drawn.

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   Form: [a, b, c, d] = PDDesign( zeta, wN, wD, inr, tSamp, sType )
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   ------
   Inputs
   ------
   zeta                Damping ratio
   wN                  Undamped natural frequency
   wD                  Derivative term cutoff
   inr                 Axis inertia
   tSamp               Sampling period*
   sType               State equation type ('Delta' or 'Z')*
                          * optional - default is a continuous controller

   -------
   Outputs
   -------
   a                   Plant matrix
   b                   Input matrix
   c                   Output matrix
   d                   Feedthrough matrix

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Children:

Common: Control/C2DZOH
Common: Control/C2DelZOH
Common: Control/FResp