functiontimeResponse
Calculate the time response of a transfer function
Extends from Modelica_LinearSystems2.Internal.timeResponseMask2_tf (Declares the common structure for the set of response functions).
Information
Syntax
(y, t, x) = TransferFunction.Analysis.timeResponse(tf, dt, tSpan, responseType, x0)
Description
First, the transfer function representation is transformed into state space representation which is given to StateSpace.Analysis.timeResponse and the time response of the state space system is calculated. The type of the time response is defined by the input responseType, i.e.
Impulse "Impulse response", Step "Step response", Ramp "Ramp response", Initial "Initial condition response".
The state space system is transformed to a appropriate discrete state space system and, starting at x(t=0)=x0 and y(t=0)=C*x0 + D*u0, the outputs y and x are calculated for each time step t=k*dt.
Example
TransferFunction s = Modelica_LinearSystems2.TransferFunction.s();
Modelica_LinearSystems2.TransferFunction tf=1/(s^2+s+1);
Real Ts=0.1;
Real tSpan= 0.4;
Modelica_LinearSystems2.Types.TimeResponse response=Modelica_LinearSystems2.Types.TimeResponse.Step;
Real x0[1]={0,0};
Real y[5,1,1];
Real t[5];
Real x[5,1,1]
algorithm
(y,t,x):=Modelica_LinearSystems2.TransferFunction.Analysis.timeResponse(tf,Ts,tSpan,response,x0);
// y[:,1,1]={0, 0.0048, 0.0187, 0.04, 0.0694}
// t={0, 0.1, 0.2, 0.3, 0.4}
// x[:,1,1]={0, 0.0048, 0.0187, 0.04, 0.0694}
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica_LinearSystems2.TransferFunction | tf (from timeResponseMask2_tf) | ||
| Real | dt (from timeResponseMask2_tf) | 0 | Sample time [s] |
| Real | tSpan (from timeResponseMask2_tf) | 0 | Simulation time span [s] |
| Modelica_LinearSystems2.Utilities.Types.TimeResponse | response | Modelica_LinearSystems2.Utilities.Types.TimeResponse.Step | |
| Real[TransferFunction.Analysis.denominatorDegree(tf)] | x0 | zeros(TransferFunction.Analysis.denominatorDegree(tf)) | Initial state vector |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real[:,1,1] | y (from timeResponseMask2_tf) | Output response: (number of samples) x (number of outputs) x (number of inputs) | |
| Real[:] | t (from timeResponseMask2_tf) | Time vector: (number of samples) | |
| Real[:,Modelica_LinearSystems2.TransferFunction.Analysis.denominatorDegree(tf),1] | x_continuous (from timeResponseMask2_tf) | State trajectories: (number of samples) x (number of states) x (number of inputs) |