2D Controller Blend

Implement 2-D vector of state-space controllers by linear interpolation of their outputs

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Libraries:
Aerospace Blockset / GNC / Control

Description

The 2D Controller Blend block implements an array of state-space controller designs. The controllers are run in parallel, and their outputs interpolated according to the current flight condition or operating point. The advantage of this implementation approach is that the state-space matrices A, B, C, and D for the individual controller designs do not need to vary smoothly from one design point to the next. The output from this block is the actuator demand, which you can input to an actuator block.

For the 2D Controller Blend block, at any given instant in time, nine controller designs are updated.

As the value of the scheduling parameter varies and the index of the controllers that need to be run changes, the states of the oncoming controller are initialized by using the self-conditioned form as defined for the Self-Conditioned [A,B,C,D] block.

Examples

HL-20 with Flight Instrument Blocks and Visualization Using Unreal Engine

Model NASA HL-20 lifting body and controller modeled in Simulink^® and Aerospace Blockset™, using Unreal Engine^® for visualization.

• Open Live Script

Limitations

This block requires the Control System Toolbox™ license.

Ports

Input

y — Aircraft measurements

vector

Aircraft measurements, specified as a vector.

Data Types: double

v1 — Scheduling variable

vector

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

Data Types: double

v2 — Scheduling variable

vector

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

Data Types: double

Output

u — Actuator demands

vector

Actuator demands, specified as a vector.

Data Types: double

Parameters

A-matrix(v1,v2) — A-matrix of the state-space implementation

A (default) | array

A-matrix of the state-space implementation. In the case of 2-D blending, 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(v1,v2) — B-matrix of the state-space implementation

A (default) | array

B-matrix of the state-space implementation. The B-matrix should have three dimensions, the last one corresponding to the scheduling variable v. For example, if the B-matrix corresponding to the first entry of v is the identity matrix, then B(:,:,1) = [1 0;0 1];.

Programmatic Use

Block Parameter: B

Type: character vector

Values: vector

Default: 'B'

C-matrix(v1,v2) — C-matrix of the state-space implementation

C (default) | array

C-matrix of the state-space implementation. The C-matrix should have three dimensions, the last one corresponding to the scheduling variable v. For example, if the C-matrix corresponding to the first entry of v is the identity matrix, then C(:,:,1) = [1 0;0 1];.

Programmatic Use

Block Parameter: C

Type: character vector

Values: vector

Default: 'C'

D-matrix(v1,v2) — D-matrix of the state-space implementation

C (default) | array

D-matrix of the state-space implementation. The D-matrix should have three dimensions, the last one corresponding to the scheduling variable v. For example, if the D-matrix corresponding to the first entry of v is the identity matrix, then D(:,:,1) = [1 0;0 1];.

Programmatic Use

Block Parameter: D

Type: character vector

Values: vector

Default: 'D'

First scheduling variable (v1) breakpoints — Breakpoints for first scheduling variable

v1_vec (default) | vector

Breakpoints for the first scheduling variable, specified as a vector. The length of v1 should be same as the size of the third dimension of A, B, C, and D.

Programmatic Use

Block Parameter: breakpoints_v1

Type: character vector

Values: vector

Default: 'v1_vec'

Second scheduling variable (v2) breakpoints — Breakpoints for second scheduling variable

v2_vec (default) | vector

Breakpoints for the second scheduling variable, specified as a vector. The length of v2 should be same as the size of the fourth dimension of A, B, C, and D.

Programmatic Use

Block Parameter: breakpoints_v2

Type: character vector

Values: vector

Default: 'v2_vec'

Initial state, x_initial — Initial states

0 (default) | vector

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'

Poles of A(v)-H(v)*C(v) — Desired poles

[-5 -2] (default)

For oncoming controllers, an observer-like structure is used to ensure that the controller output tracks the current block output, u. The poles of the observer are defined in this dialog box as a vector, the number of poles being equal to the dimension of the A-matrix. Poles that are too fast result in sensor noise propagation, and poles that are too slow result in the failure of the controller output to track u.

Programmatic Use

Block Parameter: vec_w

Type: character vector

Values: vector

Default: '[-5 -2]'

References

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

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced before R2006a