SI Estimate State-Space Model VI

SI Estimate State-Space Model (Subspace SISO Waveform)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signal specifies the input waveform of the stimulus signal.
	response signal specifies the input waveform of the response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficient of the system model.
	noise returns the disturbance e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Subspace SISO Array)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signal specifies the input array of the stimulus signal.
	response signal specifies the input array of the response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	sampling rate specifies the sampling frequency in hertz. The value of sampling rate must be greater than 0. The default is 1.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficient of the system model.
	noise returns the disturbance e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Subspace MISO Waveform)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signals specifies the input waveform array of the stimulus signals. Each element of the array is the waveform of one stimulus signal.
	response signal specifies the input waveform of the response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space (SS) model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficients of the system model.
	noise returns the disturbance e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Subspace MISO Array)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signals specifies the input array of the stimulus signals. Each row in the array is one stimulus signal.
	response signal specifies the input array of the response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	sampling rate specifies the sampling frequency in hertz. The value of sampling rate must be greater than 0. The default is 1.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space (SS) model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficients of the system model.
	noise returns the disturbance e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Subspace MIMO Waveform)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signals specifies the input waveform array of the stimulus signals. Each element of the array is the waveform of one stimulus signal.
	response signals specifies the input waveform array of the response signals. Each element of the array is the waveform of one response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space (SS) model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficients of the system model.
	noises returns the disturbances e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Subspace MIMO Array)

	structure selector determines additional matrices of the state-space model you want to estimate. D matrix? specifies whether to estimate the D matrix of the model. If TRUE, this VI estimates the D matrix. If FALSE, the D matrix is 0. K matrix? determines whether to estimate the Kalman gain matrix K. If TRUE, this VI estimates the K matrix. If FALSE, the K matrix is 0. initial states? specifies whether to estimate the initial state of the model. If TRUE, this VI estimates the initial state. If FALSE, the initial state is 0.
	stimulus signals specifies the input array of the stimulus signals. Each row in the array is one stimulus signal.
	response signals specifies the input array of the response signals. Each row in the array is one response signal.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	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 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.
	sampling rate specifies the sampling frequency in hertz. The value of sampling rate must be greater than 0. The default is 1.
	Kalman gain returns the Kalman gain of the state-space model. The dimension of Kalman gain equals number of states.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space (SS) model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficients of the system model.
	noises returns the disturbances e(t) in the estimated system 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.
	initial states returns the initial states of the state-space model. The dimension of initial states equals number of states.

SI Estimate State-Space Model (Realization SISO)

	impulse response is the input array of the impulse response.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	length specifies the number of data points of the impulse response to use when estimating the state-space model. The value must be less than or equal to the array size of the impulse response. The default is -1, which means this VI uses all data points of the impulse response.
	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 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.
	sampling rate is the signal sampling rate in hertz. The value of sampling rate must be greater than 0.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficient of the system 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.

SI Estimate State-Space Model (Realization MIMO)

	impulse responses is the input array of the impulse response.
	number of states specifies the number of states of the system model. The value of number of states must be greater than 0. The default is 4.
	length specifies the number of data points of the impulse response to use when estimating the state-space model. The value must be less than or equal to the array size of the impulse response. The default is -1, which means this VI uses all data points of the impulse response.
	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 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.
	sampling rate is the signal sampling rate in hertz. The value of sampling rate must be greater than 0.
	system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains. Note  You can use a customized system model probe to view model information that flows through system model wires when you debug a block diagram created with the System Identification VIs. Right-click a system model wire and select Custom Probe»SI System Model from the shortcut menu to use the system model probe.
	coefficients of state-space model returns the coefficients of the state-space model. A returns the A coefficients of the system model. B returns the B coefficients of the system model. C returns the C coefficients of the system model. D returns the D coefficient of the system 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.

SI Estimate State-Space Model Details

You can use the SI Estimate Orders of System Model VI to estimate the optimal order of the state-space model. In some cases, the optimal orders returned by the SI Estimate Orders of System Model VI might not be appropriate for the number of states. You can use the singular values output of the State-Space instances of the SI Estimate Orders of System Model VI to obtain the optimal number of states. You can display singular values using an XY graph. The turning point in the curve specifies the optimal number of states.

The LabVIEW System Identification Toolkit estimates discrete state-space models using two methods: the realization and the deterministic-stochastic subspace methods. The realization method uses the system impulse response as the input. You can use the SI Estimate Impulse Response VI to compute the impulse response from stimulus and response signals.

The realization method estimates only the deterministic part, A, B, C, D, of the system and does not include the stochastic part, K, in the model structure. The deterministic-stochastic subspace method includes both the deterministic and stochastic parts in the model structure. Therefore, you must choose the subspace method if you want to include the stochastic part in the model. Otherwise, you can use the realization method.

Examples

Refer to the following VIs for examples of using the SI Estimate State-Space Model VI:

• Discrete State-Space Model (Direct Method) VI: labview\examples\System Identification\Getting Started\Closed-Loop Estimation.llb

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• Estimate State-Space Model from Impulse Response VI: labview\examples\System Identification\Getting Started\Parametric Estimation.llb

   Open example  Browse related examples