modred (Control Design and Simulation Module, MathScript Function)
Member of the reduce class.
Syntax
SysRedSS = modred(SysInSS, states)
SysRedSS = modred(SysInSS, states, method)
Description
Eliminates state dynamics that you want to ignore in a state-space system model. This function can eliminate the state dynamics by deleting the states or by assuming steady-state conditions for states with fast dynamics. This assumption is a pseudo-steady-state assumption. The pseudo-steady-state assumption does not affect the discrete or continuous system gain of the original system, so the remaining states have the same gain as the full order system.
Inputs
| Name | Description | ||||
| SysInSS | Specifies a linear time-invariant (LTI) model in state-space form. | ||||
| states | Specifies the index numbers of the states you want to eliminate. states is an integer scalar or vector. | ||||
| method | Specifies the method you want to use to reduce the order of the SysInSS model. method is a string that can take the following values:
|
Outputs
| Name | Description |
| SysRedSS | Returns the reduced-order version of the SysInSS model. |
Examples
A = [-1, 0.1; 0.2, -2]
B = [0; 1]
C = [1, 0]
D = 0
states = 1
SysInSS = ss(A, B, C, D)
SysRed = modred(SysInSS, states)