# 2D Observer Form [A(v),B(v),C(v),F(v),H(v)]

Implement gain-scheduled state-space controller in observer form depending on two scheduling parameters

• Library:
• Aerospace Blockset / GNC / Control

## Description

The 2D Observer Form [A(v),B(v),C(v),F(v),H(v)] block implements a gain-scheduled state-space controller as defined in Algorithms.

The output from this block is the actuator demand, which you can input to an actuator block. Use this block to implement a controller designed using H-infinity loop-shaping, one of the design methods supported by Robust Control Toolbox.

## Limitations

If the scheduling parameter inputs to the block go out of range, they are clipped. The state-space matrices are not interpolated out of range.

## Ports

### Input

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Set-point error, specified as a vector.

Data Types: double

First scheduling variable, specified as a vector, that conforms to the dimensions of the state-space matrices.

Data Types: double

Second scheduling variable, specified as a vector, that conforms to the dimensions of the state-space matrices.

Data Types: double

Measured actuator position, specified as a vector.

Data Types: double

### Output

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Actuator demands, specified as a vector.

Data Types: double

## Parameters

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A-matrix of the state-space implementation. In the case of 2-D scheduling, the A-matrix should have four dimensions, the last two corresponding to scheduling variables v1 and v2. For example, if the A-matrix corresponding to the first entry of v1 and first entry of v2 is the identity matrix, then A(:,:,1,1) = [1 0;0 1];.

#### Programmatic Use

 Block Parameter: A Type: character vector Values: vector Default: 'A'

B-matrix of the state-space implementation. In the case of 2-D scheduling, the B-matrix should have four dimensions, the last two corresponding to scheduling variables v1 and v2. For example, if the B-matrix corresponding to the first entry of v1 and first entry of v2 is the identity matrix, then B(:,:,1,1) = [1 0;0 1];.

#### Programmatic Use

 Block Parameter: B Type: character vector Values: vector Default: 'B'

C-matrix of the state-space implementation. In the case of 2-D scheduling, the C-matrix should have four dimensions, the last two corresponding to scheduling variables v1 and v2. For example, if the C-matrix corresponding to the first entry of v1 and first entry of v2 is the identity matrix, then C(:,:,1,1) = [1 0;0 1];.

#### Programmatic Use

 Block Parameter: C Type: character vector Values: vector Default: 'C'

State-feedback matrix. In the case of 2-D scheduling, the F-matrix should have four dimensions, the last two corresponding to scheduling variables v1 and v2. For example, if the F-matrix corresponding to the first entry of v1 and first entry of v2 is the identity matrix, then F(:,:,1,1) = [1 0;0 1];.

#### Programmatic Use

 Block Parameter: F Type: character vector Values: vector Default: 'F'

Observer (output injection) matrix. In the case of 2-D scheduling, the H-matrix should have four dimensions, the last two corresponding to scheduling variables v1 and v2. For example, if the H-matrix corresponding to the first entry of v1 and first entry of v2 is the identity matrix, then H(:,:,1,1) = [1 0;0 1];.

#### Programmatic Use

 Block Parameter: H Type: character vector Values: vector Default: 'H'

Vector of the breakpoints for the first scheduling variable. The length of v1 should be same as the size of the third dimension of A, B, C, F, and H.

#### Programmatic Use

 Block Parameter: AoA_vec Type: character vector Values: vector Default: 'v1_vec'

Vector of the breakpoints for the second scheduling variable. The length of v2 should be same as the size of the fourth dimension of A, B, C, F, and H.

#### Programmatic Use

 Block Parameter: Mach_vec Type: character vector Values: vector Default: 'v2_vec'

Vector of initial states for the controller,that is, initial values for the state vector, x. It should have length equal to the size of the first dimension of A.

#### Programmatic Use

 Block Parameter: x_initial Type: character vector Values: vector Default: '0'

## Algorithms

The block implements a gain-scheduled state-space controller defined in the following observer form:

$\begin{array}{l}\stackrel{˙}{x}=\left(A\left(v\right)+H\left(v\right)C\left(v\right)\right)x+B\left(v\right){u}_{meas}+H\left(v\right)\left(y-{y}_{dem}\right)\\ {u}_{dem}=F\left(v\right)x\end{array}$

## References

[1] Hyde, R. A.. "H-infinity Aerospace Control Design — A VSTOL Flight Application." Advances in Industrial Control Series, Springer Verlag, 1995.

## Version History

Introduced before R2006a