CD Construct State-Space Model VI

Control Design VI and Function

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CD Construct State-Space Model VI

Owning Palette: Model Construction VIs

Installed With: Control Design and Simulation Module

Creates a deterministic state-space representation of a system using the matrices A, B, C, and D, and the Sampling Time (s) You must manually select the polymorphic instance to use.

This VI constructs a deterministic state-space model. You can use the CD Construct Stochastic Model VI to construct a stochastic state-space model.

Note  This VI supports specific combinations of the system matrices A, B, C, and D. Refer to Required Matrices input of the CD Verify MIMO Properties VI for a complete list of the combinations.

Details  

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

 Place on the block diagram  Find on the Functions palette

CD Construct State-Space Model (Numeric)

Sampling Time (s) defines whether the model represents a continuous-time system or a discrete-time system. If the model represents a continuous-time system, Sampling Time (s) must equal zero. If the model represents a discrete-time system, Sampling Time (s) must be greater than zero and equal to the sampling rate, in seconds, of the discrete system. The default is 0.
Note  If you use the inputs to create a continuous-time system, setting the Sampling Time (s) to a value greater than zero does not yield the discrete-time equivalent of the system. You must use the CD Convert Continuous to Discrete VI to convert the continuous-time system to the discrete-time equivalent of the system.
A specifies the system matrix that describes the dynamics of the states of the system.
B specifies the input matrix that relates the inputs to the states.
C specifies the output matrix that relates the outputs to the states.
D specifies the transmission matrix that relates the inputs to the outputs.
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 only if no 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.
State-Space Model returns the created numeric model. The data consists of the arrays A, B, C, and D. To access and modify the data in the model, use the Model Information VIs.
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 Construct State-Space Model (Symbolic)

Sampling Time (s) defines whether the model represents a continuous-time system or a discrete-time system. If the model represents a continuous-time system, Sampling Time (s) must equal zero. If the model represents a discrete-time system, Sampling Time (s) must be greater than zero and equal to the sampling rate, in seconds, of the discrete system. The default is 0.
Note  If you use the inputs to create a continuous-time system, setting the Sampling Time (s) to a value greater than zero does not yield the discrete-time equivalent of the system. You must use the CD Convert Continuous to Discrete VI to convert the continuous-time system to the discrete-time equivalent of the system.
Symbolic A is the symbolic representation of the system matrix that describes the dynamics of the states of the system.
Symbolic B is the symbolic representation of the input matrix of the system that relates the inputs to the states.
Symbolic C is the symbolic representation of the output matrix that relates the outputs to the states.
Symbolic D is the symbolic representation of the transmission matrix that relates the inputs to the outputs.
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 only if no 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.
Variables contains the name and value of each variable.
Name is a variable name this VI uses to define the data of the system model. Variable names can be a combination of letters and numbers. A variable name that begins with a capital letter E can produce unpredictable errors if parts of the original string represent numbers like 1E–2. Avoid terms beginning with E in such cases.
Value is the numeric value this VI associates with the variable. The VI uses this value to evaluate the model.
State-Space Model returns the created model. The data consists of the arrays Symbolic A, Symbolic B, Symbolic C, and Symbolic D in which this VI evaluates string elements using data of the Variables array. To access and modify the data in the model, use the Model Information VIs.
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 Construct State-Space Model Details

This VI does not support delays directly. To add a delay to the model, use the CD Set Delays to Model VI. Refer to the LabVIEW Control Design User Manual for more information about delays.

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