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Tuning Your Design with new Simulink Control ToolsRohit ShenoySimulink® Control Tools Marketing

6th June 2007

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Presentation Overview

Multi-loop control designOverview of multi-loop compensator design in Simulink®

Guidance control system design using a Simulink model of an HL-20 lifting body

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Multi-Loop Control Design

Coupled Multi-Loop Control

Coupled Dynamics

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Challenges of Control DesignFeedback structure may be fixed and controllers are distributedMulti-Loop Design has inherent loop interaction effectsMany controllers are fixed structure, ex:

Feedback Control Elements

Controllers

( )1

1

ττ+

=s

sG

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Application HL-20 Lifting Body

Low cost re-entry vehicleNose-first, horizontal, and unpowered landingControl system design tasks

Task 1: Flight control system designTask 2: Guidance glideslopereference tracking and disturbance rejectionTask 3: Guidance yaw and roll correctionsTask 4: Landing gear control

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HL-20 – Glideslope Control Problem

h

dDesired Height

Actual Height

To Angle of AttackCommand

Feedback Controller

Goal: Build a feedback controller to controlthe height of the aircraft given the distance to the runway

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Cross Wind

Lateral Glideslope Regulation

Flight path must remain within the coneNeed to devise controller to reject the cross wind disturbanceNearing landing need to recover any roll angle for a clean landing

Landing Cone to hitrunway

Use Roll to Bank Aircraft

Automaticroll recoveryat landing

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Side Gust Control

Build a bump-less transfer controller (A) to switch between

(B) Controlling the drift of the aircraft due to cross wind(C) Recovering the roll angle at landing

B

C

A1

Out1Xe Phi Desired

y Control

y Control State

Euler

Phi Control Enable

Phi Desired

Phi Recovery Control

Xe

y Control

Phi Control

Phi desired

Switch Signal

Controller Switching Logic

1In1

<Xe>

<Euler>

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Designing Compensators in Simulink® in R2006a

1. Build a control system in Simulink –model plant and layout control structure

2. From Simulink Control Design pick blocks to tune and auto-linearize model

3. Tune blocks using graphical design• One-click automated design• Interactive design• Simulink Response Optimization to meet time and frequency requirements

4. Write block parameters directly back to Simulink

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Design Goals

Robustness Requirement:AoA Loop maintain a phase margin > 35 degrees

Height reference trackingStep Response

Time (sec)

Ampl

itude

0 2 4 6 8 10 12-1

-0.5

0

0.5

1

1.5

2

h

d

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Closed Loop Performance GoalsDisturbance rejection:•Phi Loop maintain a phase margin > 40 degrees

Step Response

Time (sec)

Ampl

itude

0 10 20 30 40 50 60 70-0.02

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16Cross Wind

0 1 2 3 4 5 6-0.2

0

0.2

0.4

0.6

0.8

1

Time (sec)

Gus

t Siz

e

Cross Wind Disturbance

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Conclusions

New integrated workflow interface centered around SimulinkBuild any control structure in Simulink and tune the compensators using these toolsTune multi-loop control systems in a single design environmentUse graphical numerical optimization for compensator tuning, including frequency domain requirements

For more: Exhibit – Control System Design in Simulink