CD Minimal Realization VI

Control Design VI and Function

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CD Minimal Realization VI

Owning Palette: Model Reduction VIs

Installed With: Control Design and Simulation Module

Simplifies the model by using the minimum order possible to fully describe the dynamic system. The data type you wire to the State-Space Model input determines the polymorphic instance to use.

A minimal realization for a state-space model is a state-space representation in which you remove all states that are not observable or controllable. A minimal realization for transfer function and zero-pole-gain models is a representation where you use zero-pole cancellations to reduce the number of modes required to describe the system dynamics.

For state-space models, this VI uses the staircase transformation to first obtain a group of controllable states. After identifying the controllable states, this VI uses the staircase transformation again to specify which of the controllable states also are observable. The minimal realization consists of the controllable and observable states of the system.

Details  

Use the pull-down menu to select an instance of this VI.

 Place on the block diagram  Find on the Functions palette

CD Minimal Realization (State-Space)

State-Space Model contains a mathematical representation of and information about the original state-space model this VI reduces.
Tolerance specifies the threshold this VI uses to determine modes to eliminate. For state-space models, Tolerance specifies the controllability and observability thresholds. For transfer function and zero-pole-gain models, Tolerance also specifies zero-pole cancellation closeness. The default is 1E–12.
error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally even if an error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
Reduced Model represents the minimal realization of the system model. To access and modify the data in the model, use the Model Information VIs.
Number of States Removed returns the number of states this VI removes from the model to generate a minimal realization of the original state-space model.
error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

CD Minimal Realization (Transfer Function)

For transfer function models, this VI searches for the closest zero to each pole of the dynamic system. If the closest zero is within the threshold that the Tolerance specifies, this VI removes the zero-pole pair and reduces the system order.

Transfer Function Model contains a mathematical representation of and information about the original transfer function model this VI reduces.
Tolerance specifies the threshold this VI uses to determine modes to eliminate. For state-space models, Tolerance specifies the controllability and observability thresholds. For transfer function and zero-pole-gain models, Tolerance also specifies zero-pole cancellation closeness. The default is 1E–12.
error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally even if an error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
Reduced Model represents the minimal realization of the system model. To access and modify the data in the model, use the Model Information VIs.
Number of Poles-Zeros Removed returns the number of pole-zero pairs this VI removes from each input-output pair of a model. The ijth element of this parameter corresponds to the number of pole-zero pairs this VI removes from the equation at the ith output and jth input location.
error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

CD Minimal Realization (Zero-Pole-Gain)

For zero-pole-gain models, this VI searches for the closest zero to each pole of the dynamic system. If the closest zero is within the threshold the Tolerance specifies, this VI removes the zero-pole pair and reduces the system order.

Zero-Pole-Gain Model contains a mathematical representation of and information about the original zero-pole-gain model this VI reduces.
Tolerance specifies the threshold this VI uses to determine modes to eliminate. For state-space models, Tolerance specifies the controllability and observability thresholds. For transfer function and zero-pole-gain models, Tolerance also specifies zero-pole cancellation closeness. The default is 1E–12.
error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally even if an error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
Reduced Model represents the minimal realization of the system model. To access and modify the data in the model, use the Model Information VIs.
Number of Poles-Zeros Removed returns the number of pole-zero pairs this VI removes from each input-output pair of a model. The ijth element of this parameter corresponds to the number of pole-zero pairs this VI removes from the equation at the ith output and jth input location.
error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

CD Minimal Realization Details

This VI supports delays. Refer to the LabVIEW Control Design User Manual for more information about delays.

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