.Modelica_LinearSystems2.DiscreteStateSpace.Conversion.toDiscreteTransferFunction

Information

Syntax

dtf = DiscreteStateSpace.Conversion.toDiscreteTransferFunction(dss)

Description

Computes a DiscreteTransferFunction record

           n(z)     b0 + b1*z + ... + bn*z^n
  dtf = -------- = --------------------------
           d(z)     a0 + a1*z + ... + an*z^n

The algorithm uses toDiscreteZerosAndPoles to convert the discrete state space system into a discrete zeros and poles representation first and after that DiscreteZerosAndPoles.Conversion.toDiscreteTransferFunction to generate the transfer function.

Example

  Modelica_LinearSystems2.DiscreteStateSpace dss=Modelica_LinearSystems2.DiscreteStateSpace(
      A = [0.9048, 0.0,    0.0;
            0.0,   0.8187, 0.0;
            0.0,   0.0,    0.7408],
      B = [0.09516;
           0.09063;
           0.0],
      C = [1.0,1.0,1.0],
      D = [0.0],
      B2 = [0, 0;
            0, 0;
            0, 0],
      Ts = 0.1);

 algorithm

  dtf:=Modelica_LinearSystems2.DiscreteStateSpace.Conversion.toDiscreteTransferFunction(dss);

//             0.185797*z - 0.159922
//   dtf = -------------------------------
//           z^2 - 1.72357*z + 0.740818

Interface

function toDiscreteTransferFunction
  import Modelica;
  import Modelica_LinearSystems2;
  import Modelica_LinearSystems2.DiscreteTransferFunction;
  import Modelica_LinearSystems2.DiscreteStateSpace;
  import Modelica_LinearSystems2.DiscreteZerosAndPoles;
  input DiscreteStateSpace dss "Discrete state space system";
  output DiscreteTransferFunction dtf "Discrete transfer function description of system";
end toDiscreteTransferFunction;

Revisions