sicver project: onboard fault-tolerant path planning and robust fault diagnosis for reentry vehicles

ARA Days, 21-23 October 2008, Arcachon, France1

V. Morio, A. Falcoz, D. Henry, F. Cazaurang, A. Zolghadri

Automatic Control Group - IMS lab / Université de Bordeaux

Onboard Fault Tolerant Path Planning and Robust Fault Diagnosis

for Reentry Vehicles

SICVER Project


Plan of talk

Motivations, context

Objectives

Global architecture

– Onboard fault tolerant path planning

– FDIR

Concluding remarks


IMS-Bordeaux

Professors and

Associate Professors

109

Full Researchers 11

Laboratory technicians 55

Administrative

employees

14

Post-Doc 12

PhD students 128

TOTAL 329


Research Organization

MCM

Department

COFI

Department

LAPS

Department

Mic

rosyste

ms

Mate

rials

Bio

-Ele

ctro

magnetic

s

Desig

n

Nanoele

ctro

nic

s

Relia

bility

Sig

nal

Auto

matic

Contro

l

Pro

ductio

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ARIA team


ARIA Know-how and Competences : methodology

See : http://extranet.ims-bordeaux.fr/aria

Robust model-based FDIR techniques

– Design: LTI and LPV models

– Analysis, validation and assessment of diagnosis performances

– Decision for signal-based FDI

Robust G&C strategies for nonlinear systems

– NL control

– Path planning

– Fault tolerant control

http://extranet.ims-bordeaux.fr/aria




Overview of ARIA Know-how and Competences : Aerospace systems

European GARTEUR program : (AG16), FDI/FTC

Objective : Developpement of new FTC strategies for

flight control

Xrun

way

Zrun

way

Yrun

way

Final

approach

Fault

Airport



Airbus France : FDI of oscillatory faults in flight control system for

up-coming Airbus programs : A400M, A350, A3X

Le 29 novembre 2007 Page 3

© A

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US

S.A

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ll ri

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reserv

ed.

Confidential

and p

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ocum

ent.

Fligth Control Computer

Analogic Ouput

Analogic Input

Rod Sensor

Actuator

Fligth Control Laws

K

Control Surface Sensor

Hydraulic Servocontrol

ou

EHA

: OFC sources

COM

MON

Analogic Input

(Command)

Oscillatory Failure Case localization in a servoloop control

• Oscillatory Failure Case ( OFC ) detection in control surface

servoloop

4 Improvement of the method currently implemented onboard

on A380 for future programs (A400M, A350, A30X, ...)

– Decrease load effects on structure

– Lower detection threshold

– Lower detection time

– New actuators (EHA, EBHA)

Problem Setting


– Leader of SIRASAS project (French)

– Two topics (FDIR) :

• Satellite systems

• Aeronautical systems



ARIA Know-how and Competences : Aerospace systems

– ADDSAFE project (FP7): – Advanced Fault Diagnosis for Safer Flight Guidance and Control– Starting time : January 2009

– For more information see : http://extranet.ims-bordeaux.fr/aria





Context

SICVER falls within the scope of the

« Aerospace Valley » cluster : Aerospace and

Embedded Systems

http://www.aerospace-valley.com


Motivations To answer the question : could new methods, recently developed

within the academic community, be used to improve the

performances of existing in-service schemes for next generation

RLV, while respecting the stringent operational constraints

(robustness, cpu time, …) ?

Observation : gap between

the methods being developed by the academic community,

and

those currently in use by the industrial end-users.

SICVER >>> an attempt to answer the above question …


Objective

Innovative technical solutions for increasing

spacecraft autonomy >>> decreasing the ground

level intervention load.

model-based Fault Detection, Identification

and Recovery (FDIR) challenges for G&C,

Fault tolerant path planning, onboard

trajectory reshaping.


Work breakdown

• PhD 1: Onboard replanning of

optimal TAEM and autolanding

trajectories in order to overcome

any faulty scenario (V. Morio)

• PhD 2: Robust Fault Detection

and Isolation and Identification

with a high level of sensitivity wrt

faults (A. Falcoz)

• Starting time : October 2006

• End : September 2009


Common goal

The two topics are not independent :

To access the remaining capabilities of the

vehicle

Under faulty conditions : how to recover

timely the vehicle control and guidance

capability to avoid out-of-tolerance

conditions.


Considered Atmospheric Re-entry Mission

Orbiter

ground track

TEP

NEP

Hypersonic phase

Zrunway

TAEM phase

Autolanding

phase

Injection point


TAEM and autolanding phases

HAC3

HAC1

TEP

HAC4

Preliminary

dissipation S-turn

Xrunway

Zrunway

Yrunway

HAC acquisition

S-turn

HAC2

NEP


Available models at IMS

Estimated main features

L/D (for M < 2) between 2 and 3

mass 2000 kg

length 5.9 m

Sref 8.97 m2

ARES-H

HL-20

Shuttle Orbiter


Max L/D (for M < 2) 3.2

mass 10,400 kg

length 8.32 m

Sref 26.61 m2


Max L/D (for M < 2) 4

mass 75,000 kg

length 37.24 m

Sref 249.9 m2


Available models at IMS


Shuttle, on going …

19/61


General setup

Supervision

layer

GNC module

Navigation

unit

Nominal

controls

Attitude

controller

Actuators

Allocation

Flight control

Unit

Vehicle

NL model

Path

planning

Guidance

controller

Nominal

Guidance

Guidance Unit


Results : Path planning and trajectory

reshaping

Flatness of the guidance model >>> Original Optimal Control

problem is transformed into a “geometric” and “integration-free”

setup

Convex approximation of nonlinear nonconvex constraints >>>

superquadric shapes

Genetic algorithms to find a global solution


Results: path planning and trajectory

reshaping


Results: Path plannig and trajectory

reshaping


TAEM Guidance


Results : Fault diagnosis

Take into account the coupling between the in-plane and out-of-

plane vehicle motions, as well as the effects that the faults could

have on the GNC performances

Robust FDI filters based on Hinfinity/H- theory

Formalized validation process and test (allows for easy re-tuning)

Complete cycle of design/validation


Residual generation

Desision

making

Faulty

actuator

Fault identification

FDIR

dispersions

Navigation

TG Guidance loop Attitude control

Dynamics


Results: FDI, HL20 vehicle

Attitude control loop model


Results: FDI (flap fault)

modelling errors


FDI, flap fault


Concluding remarks

Important methodological results, over 15 publications

Need for a common high-fidelity and modular RLV

benchmark for design, tuning and validation

specify a set of predefined scenarios to be tested

Techniques/algorithms need to be more systematically

structured at GNC functional level, up to global System &

Operation level

sicver project: onboard fault-tolerant path planning and robust fault diagnosis for reentry vehicles

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