functioninitialResponse

Calculate the initial time response of a discrete transfer function

Extends from Modelica_LinearSystems2.Internal.timeResponseMask_tf_discrete (Declares the common structure for the set of discrete response functions).

Information

Syntax

(y, t, x) = DiscreteTransferFunction.Analysis.initialResponse(x0, dtf, tSpan)

Description

First, the discrete transfer function representation is transformed into discrete state space representation which is given to DiscreteStateSpace.Analysis.timeResponse and the initial response of the discrete state space system for initial state x0 is calculated. The type of the time response is defined by the input responseType, i.e. in this case

Initial "Initial response",

The outputs y and x of the discrete state space systrem are calculated for each time step t=k*dt.

Example

  DiscreteTransferFunction z = Modelica_LinearSystems2.DiscreteTransferFunction.z();
  Modelica_LinearSystems2.DiscreteTransferFunction dtf=(0.0023753*z^2 + 0.00475059*z + 0.0023753)/(z^2 - 1.89549*z + 0.904988);

  Real tSpan= 0.4;
  Real x0[1]={1,2};

  Real y[5,1,1];
  Real t[5];
  Real x[5,1,1]

algorithm
  dtf.Ts:=0.1;
  (y,t,x):=Modelica_LinearSystems2.DiscreteTransferFunction.Analysis.initialResponse(x0,dtf,tSpan,response,x0);
//  y[:,1,1] = {0.0187315575967189, 0.0271552102903869, 0.0345205091861731, 0.0408580313775029, 0.0462052138701078}
//         t = {0, 0.1, 0.2, 0.3, 0.4}
//  x[:,1,1] = {1.0, 2.0, 2.88598574821853, 3.66037203581564, 4.3264045475288}

Inputs

TypeNameDefaultDescription
Real[:]x0fill(0, 0)Initial state vector
Modelica_LinearSystems2.DiscreteTransferFunctiondtf (from timeResponseMask_tf_discrete)
RealtSpan (from timeResponseMask_tf_discrete)0Simulation time span [s]

Outputs

TypeNameDefaultDescription
Real[:,1,1]y (from timeResponseMask_tf_discrete)Output response: (number of samples) x (number of outputs) x (number of inputs)
Real[:]t (from timeResponseMask_tf_discrete)Time vector: (number of samples)
Real[:,Modelica_LinearSystems2.DiscreteTransferFunction.Analysis.denominatorDegree(dtf),1]x_discrete (from timeResponseMask_tf_discrete)State trajectories: (number of samples) x (number of states) x (number of inputs)