PLECS 2.0 Online Help

Impulse Response Analysis

Purpose

Perform an impulse response analysis.

Library

Extras/Analysis Tools

Description

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The Impulse Response Analysis block enables you to determine the transfer function of a generic system from a single input to one or more outputs. The analysis is performed by injecting a small rectangular pulse into the system and computing the inverse Laplace tranform of the system response(s). The perturbation signal is available at the block output. The system outputs to be analyzed must be fed into the block's input port.

An analysis can be started either by clicking the button Start analysis or with the MATLAB command

plimpulseresponse(block);

where block is the Simulink handle or the full block path of the Impulse Response Analysis block. The block handle or path can be followed by parameter/value pairs that override the settings in the dialog box.

For additional information see section Impulse Response Analysis.

Parameters and Dialog Box

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System period length
The period length of the unperturbed system.
Simulation start time
The simulation start time for the impulse response analysis.
Frequency sweep range
A vector containing the lowest and highest perturbation frequency.
Frequency sweep scale
Specifies whether the sweep frequencies should be distributed on a linear or logarithmic scale.
Number of points
The number of data points generated.
Perturbation
The amplitude of the perturbation signal.
Compensation for discrete pulse
Specifies whether and how the effect of the sampling should be compensated. See section Compensation for Discrete Pulse for an explanation of the parameter values.
Termination tolerance
The relative error bound used in the initial steady-state analysis.
Max number of iterations
The maximum number of iterations allowed during the initial steady-state analysis.
Output variable
The name of a MATLAB variable used to store the transfer function at the end of an analysis. If the analysis was run interactively from the GUI, the variable is assigned in the MATLAB base workspace. If the analysis was run with the placsweep command, the variable is assigned in the caller's workspace.
Plot bode diagram
Specifies whether to plot the transfer function in a bode diagram.
Display level
Specifies the level of detail of the diagnostic messages displayed in the command window (iteration, final, off).
Hidden model states
Specifies how to handle Simulink blocks with 'hidden' states, i.e. states that are not stored in the state vector (error, warning, none).