append

Group models by appending their inputs and outputs

Syntax

sys = append(sys1,sys2,...,sysN)

Description

sys = append(sys1,sys2,...,sysN)appends the inputs and outputs of the modelssys1,...,sysNto form the augmented modelsysdepicted below.

For systems with transfer functionsH₁(s), . . . ,H_N(s), the resulting systemsys有block-diagonal我国航天er function

$[\begin{matrix} H_{1} (s) & 0 & \dots & 0 \\ 0 & H_{2} (s) & \dots & ⋮ \\ ⋮ & ⋮ & ⋱ & 0 \\ 0 & \dots & 0 & H_{N} (s) \end{matrix}]$

For state-space modelssys1andsys2with data (A₁,B₁,C₁,D₁) and (A₂,B₂,C₂,D₂),append(sys1,sys2)produces the following state-space model:

$\begin{matrix} [\begin{matrix} {\dot{x}}_{1} \\ {\dot{x}}_{2} \end{matrix}] = [\begin{matrix} A_{1} & 0 \\ 0 & A_{2} \end{matrix}] [\begin{matrix} x_{1} \\ x_{2} \end{matrix}] + [\begin{matrix} B_{1} & 0 \\ 0 & B_{2} \end{matrix}] [\begin{matrix} u_{1} \\ u_{2} \end{matrix}] \\ [\begin{matrix} y_{1} \\ y_{2} \end{matrix}] = [\begin{matrix} C_{1} & 0 \\ 0 & C_{2} \end{matrix}] [\begin{matrix} x_{1} \\ x_{2} \end{matrix}] + [\begin{matrix} D_{1} & 0 \\ 0 & D_{2} \end{matrix}] [\begin{matrix} u_{1} \\ u_{2} \end{matrix}] \end{matrix}$

Arguments

The input argumentssys1,...,sysNcan be model objects s of any type. Regular matrices are also accepted as a representation of static gains, but there should be at least one model in the input list. The models should be either all continuous, or all discrete with the same sample time. When appending models of different types, the resulting type is determined by the precedence rules (seeRules That Determine Model Type(Control System Toolbox)for details).

There is no limitation on the number of inputs.

Examples

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Append Inputs and Outputs of Models

This example uses:

Control System Toolbox Control System Toolbox

Open Live Script

Create a SISO transfer function.

sys1 = tf(1,[1 0]); size(sys1)

Transfer function with 1 outputs and 1 inputs.

Create a SISO continuous-time state-space model.

sys2 = ss(1,2,3,4); size(sys2)

State-space model with 1 outputs, 1 inputs, and 1 states.

Append the inputs and outputs ofsys1, a SISO static gain system, andsys2. The resulting model should be a 3-input, 3-output state-space model.

sys = append(sys1,10,sys2)

sys = A = x1 x2 x1 0 0 x2 0 1 B = u1 u2 u3 x1 1 0 0 x2 0 0 2 C = x1 x2 y1 1 0 y2 0 0 y3 0 3 D = u1 u2 u3 y1 0 0 0 y2 0 10 0 y3 0 0 4 Continuous-time state-space model.

size(sys)

State-space model with 3 outputs, 3 inputs, and 2 states.

Version History

Introduced in R2012a