feedback (Control Design and Simulation Module, MathScript Function)

Member of the connect class.

Syntax

SysClosed = feedback(SysIn_1, SysIn_2)

SysClosed = feedback(SysIn_1, SysIn_2, sign)

Description

Connects two system models together to produce a closed-loop model using negative or positive feedback connections. The models must be either continuous models or discrete models with identical sampling times. Refer to the LabVIEW Control Design User Manual for information about connecting models together in a closed-loop configuration.

Examples

Inputs

Name	Description
SysIn_1	Specifies a linear time-invariant (LTI) model in transfer function, zero-pole-gain, or state-space form.
SysIn_2	Specifies a linear time-invariant (LTI) model in transfer function, zero-pole-gain, or state-space form.
sign	Specifies whether the feedback connections are negative or positive. sign is an integer scalar that takes the following values: -1 (Default) Specifies that you want the feedback connections to be negative. 1 Specifies that you want the feedback connections to be positive.

Outputs

Name

Description

SysClosed

Returns a closed-loop LTI model consisting of SysIn_1 and SysIn_2 connected together in a closed-loop configuration. All connections are of the type you specify using the sign input. SysClosed is a model in transfer function, zero-pole-gain, or state-space form. If the input models are not of the same form, the following hierarchy determines the form of the SysClosed model: state-space>zero-pole-gain>transfer function. For example, if the SysIn_1 model is in state-space form and the SysIn_2 model is in zero-pole-gain form, the SysClosed model is in state-space form.

Examples

SysIn_1 = tf([1, 1], [1, -1, 3])
SysIn_2 = zpk([1], [1, -1], 1)
SysClosed = feedback(SysIn_1, SysIn_2, 1)

Related Topics

append
parallel
series