hybrid workgroup pam binns magnus carlsson david corman bonnie heck tom henzinger gokhan inalhan...
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Hybrid WorkgroupPam Binns
Magnus Carlsson
David Corman
Bonnie Heck
Tom Henzinger
Gokhan Inalhan
Gabor Karsai, co-chair
Wallace Kelly
Edward A. Lee, chair
Brian Mendel
Andrew Moran
Linda Wills
Modeling Questions
Language (syntax, semantics, composition) Modeling a distributed physical plant Modeling the controller Modeling faults and their effects How are models used? Semantics of anytime computation
Uses of Hybrid Systems
Analysis– Analysis of discrete and continuous controllers
interacting with a continuous plant Simulation
– Evaluation of continuous models with discrete mode transitions
Embedded modeling– Embedding of continuous models in deployed
systems, integrated into the control algorithms (e.g. for fault identification)
Questions
What's in the OCP, and what's in the application? Run-time support for hybrid models? at what cost? Design-time support? (e.g. generation of software) Anytime computation? (resource management) QoS guarantees? Is real-time O/S the only option? Admission control? Support for domain-specific languages?
Examples Considered
UAV helicopter control (GATech) Free flight conflict avoidance (Rockwell) Platooning vehicles (Berkeley) Dragonfly – Multi-vehicle coord (Stanford)
In all cases, we talked about fault detection and adaptation using modal control.
Mode Transition Control (GATech)Overall Architecture
MissionPlanning
SituationAwareness
Mode TransitionControllers
ModeTransitionManager
MTC #1
MTC #2
MTC #N
FlightController
ModeSelection
Goal Mode
TransitionStart Flag
TransitionComplete Flag
Helicopter States
Mode Transition Control Manager
Mode Transition Specification
Mode1 Mode2
ModeN
TransitionStart Flag
TransitionComplete Flag
DesiredGoal Mode
11
22
N 2
2N
21
12
1N
N1
NN
ij
ii
---- denotes a transition from Modei to Modej
---- denotes a regulation about Modei
FDI/FTC Demo in OCP (GATech)
Subsystem
Local Controller
Subsystem
Local Controller
InterconnectionStructure
ReconfigurationController
RedistributionController
Set-PointController
Fault TolerantControl Manager
Fault Detection& Identification
HighLevel
HighLevel
MidLevel
MidLevel
LowLevel
LowLevel
e1
v1
r1y1
Indicates separate OCP components
Free Flight (Rockwell)
Extensions
UCAVs with accurate models of one another – coordinated maneuvers rather than assuming the other aircraft will not react.
Errors in transmission, faulty/damaged UCAVs – fault identification and adaptation.
Create hybrid automaton model and use hybrid Mocha to verify that conflicts do not occur.
Scenario – Vehicle Tracking
Publishes:• time • driving force• velocity• position
Event Channel
Implements:• fault detection • modal control
Subscribes
Modeling Car Tracking
Force car m odel pub lishe r
lead ing car
pub lishe r
force
speed
position
m onitor
subsc
subsc
Alarm
pub l
pub l
too close
too far
fau ltde tection
car m odelsubsc
fo llow ing car
pub lishe r
TrackingController
(P ID)
Bang-BangController
m odalcontro lle r
Java Space (today)OCP (tomorrow)
thanks to Jie Liu and Xiaojun Liu
Execution
sensors
leader
Br Acc
Ba
bang-bang PID
follower
controller actuators
S
Hierarchical ViewOCP here only?
Styles of Publish and Subscribe Interactions
time stamped events? globally time stamped? reliable delivery? ordered delivery? signal coordination? synchronous delivery? blending of multiple publishers? dynamic redirection/resourcing? persistence? history?
OCP Domain #1
time stamped events? yes globally time stamped? no reliable delivery? yes ordered delivery? no signal coordination? yes globally synchronous delivery? no blending of multiple publishers? no dynamic redirection/resourcing? yes persistence? no history? no
What is a Domain
The definition of the interaction of components, and the software that supports this interaction.
Multi-domain modeling means: Hierarchical composition
– heterogeneous models allowed
Domains can be specialized– avoid creeping featurism– enable verification
Data replication in OCP/Boldstroke is another domain– separation of communication mechanisms.
What technology can be shared when building domains?
Abstract syntax Type systems Components Interfaces …
sensors
leader
Br Acc
Ba
bang-bang PID
follower
controller actuators
S
Domains After Domain 1
High-sample-rate, periodic event handling Stream-based component interaction Control reconfiguration management Time-triggered, synchronous modeling Continuous-time domain
Domains need to be able to: Share a consistent notion of time Share signals/params across levels of the hierarchy. Export interfaces to other domains Import components designed in another domain
Milestones
Use OCP in demonstrations in each of– Active state models– On-line control customization– Coordinated multi-modal control
Steps– Define the challenge problems that justify domains.– Work out how mode transitions and other control
reconfiguration are handled in the OCP.– Work out the interaction semantics (domains)
supported by the OCP (mode transition control? continuous modeling? synchronous interactions?)
Architecture to Avoid
Poor common infrastructure. Weak specialization.Poor resource management and sharing. Poor planning.
Also to Avoid
Elegant, unified, and beautiful, but rigid, inflexible, and difficult to adapt. Plus, it takes 100 years to build.
Elegant Federation
Elegant federation of heterogeneous models.
Two Rodeo Drive, Kaplan, McLaughlin, Diaz
Sourc
e:
Kapla
n M
cLaugh
lin D
iaz,
R. R
appaport
, R
ock
port
, 1
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