Download - Integrated chassis control Brakenet 2002
Integrated Vehicle Control SystemsIntegrated Vehicle Control Systems
Vehicle Chassis SystemsVehicle Chassis SystemsControl Control
and and IntegrationIntegration
September, 2002September, 2002
Dr. Mark N.W. HowellDr. Mark N.W. Howell
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• IntroductionIntroduction
• Systems IntegrationSystems Integration
• Subsumption ArchitectureSubsumption Architecture
• ExamplesExamples
• ConclusionsConclusions
Presentation OutlinePresentation Outline
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Safety• Predictable behaviour• Responsive Handling • Ride Comfort
• Maximise efficiency & performance of the vehicle• Flexibility, modular, ‘plug and play’ architecture
IntroductionIntroduction
Integrated Vehicle Control SystemIntegrated Vehicle Control System
OEMOEMRequirementsRequirements
Based on car type/OEM requirements
select required systems for interaction
Brand DNA Product Differentiation
Performance FeelPerformance Feel
Ease of UseEase of Use
ReliabilityReliability
IntegrityIntegrity
SafetySafety
ComfortComfort
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Whole Vehicle Objectives
Braking Steering
Suspension Powertrain
6 D.O.F
Longitudinal Lateral Bounce Pitch Roll Yaw
Characteristics
Safe Predictable Responsive Handling Ride ComfortNVH, Energy, Reliability, Cost ...
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Braking Systems - ABS, TRC
• Steering - AFWS, 4WS
• Suspension - Active, Semi-active, Roll Control
• Drivetrain - Differential/ IVT/CVT
• + Cruise Control, Intelligent/Adaptive Cruise Control
• Yaw moment control, X-by-wire
• Future systems: Collision Avoidance, Parking
• Need a coherent way of integrating systems
The Need for IntegrationThe Need for Integration
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Modular
• Respect IPR of suppliers
• Avoid excessive complexity
• Incorporate fault detection, diagnosis and tolerance
• Open architecture
Design RequirementsDesign Requirements
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Subsumption Architecture Subsumption Architecture
Sensors
STIMULUS
COORDINATIONO
Actuators
Behaviour 1
Behaviour 2
Behaviour n
A modular, behaviour based, distributed architecture
Behaviours are layers of control architectures that are event driven
One layer can subsume control over another layer
Higher level behaviour can suppress a lower-level behaviour.
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Distributed Layered Control– Control distributed across parallel layers each with multiple modules
• Behavioural Decomposition– different layers support different ‘task-achieving’ behaviours’ – decomposes into behavioural rather than function units
• Increasing ‘Levels of competence’– Ascending level adds capabilities resulting in higher overall competence.– Higher levels often operate by modulating the activities of lower levels.
• Incremental Construction– incremental control system designing – intermediate architecture tested and debugged before next layer added.
• Conflict resolution and communication between levels– Higher layers subsume the roles of lower ones by suppressing their
outputs and substituting their own.
Key Aspects of SubsumptionKey Aspects of Subsumption
Integrated Vehicle Control SystemIntegrated Vehicle Control System
SubsumptionSubsumptionAdvantages
• Modular
• Very flexible
• Robust to system change
• Incremental control design Disadvantages
• Complex overall system with a large number of behaviours
• Verification difficult of overall system behaviour
Integrated Vehicle Control SystemIntegrated Vehicle Control System
CollisionAvoidance
StraightLine
Stability
NeutralSteer
ParkingAid
SafetyDistance
from Obstacles
Anti -Dive
Anti -Squat
YawStability
RollStability
RideComfort
LoadTransfer
ForwardSpeed
Layer 4
Behaviour
Layer 3
Behaviour
Layer 2
Behaviour
Layer 1
Behaviour
Layer 0
Hardware
ABS TCSSide SlipControl
ControllableSuspension
DriverSen
sor
and
Info
rmat
ion
Bus
Integrated Layers
Non Integrated Layers(mostly single loop)
Lane Detectionand Tracking
Brakes Engine Transmission Suspension Steering
Subsumption SubsystemsSubsumption Subsystems
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Sensors(physical)
Sensors(Soft)
State Estimation/Observers
Near TrafficCondition
Driver ModelTrue Vehicle
Model'Desired' Vehicle
Model
Road ConditionEstimation
Bah
avio
urs
Lane Detection
Sensor and Information BusSensor and Information Bus
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Behaviour 4
Behaviour 3
Behaviour 2
Behaviour 1
ACTION
MAX (B1, B2,B3,B4)
Behaviour 4
Behaviour 3
Behaviour 2
Behaviour 1
ACTION
Respond of highestactive behaviour
Response of behaviourwith the highestactivation signal
Behaviour 4
Behaviour 3
Behaviour 2
Behaviour 1
ACTION
Voting based (Neural)
Behaviour 4
Behaviour 3
Behaviour 2
Behaviour 1
ACTION
Fuzzy Rule based
(A)
(B)
(C)
(D)
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Scope for Integration - ActuationScope for Integration - Actuation
• 4 Independent Brake 4
• Engine 1+(...)
• Driveline (Transmission/differential) 1,2+
• Individual Wheel Steering 4
• Active Suspension 4
Total : 15+
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Stiff suspension model - nonlinear tyre model
• 7 DOF: Yaw, Sideslip, Longitudinal, Wheel spin + Control States
• Independent wheel braking
• Rudimentary Powertrain (torque demand)
• Active Front Wheel Steer
Simple StudySimple Study
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Integrated Systems
• Non-integrated control
Driver
Throttle Brake Input
Steer AngleInput
Brake torque
Front Steer Angle
Throttle
Low
‘ABS’ Independent Wheel Slip Control
Front Slip angle control
Yaw/ Sideslip
Control
Directional
Control
HighIntermediate
Vehicle
Simple study - levels of behaviourSimple study - levels of behaviour
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-10
-5
0
5
10
15
20
25
30
time [s]
sp
ee
d [
m/s
]Vehicle Forward Speed
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-200
-150
-100
-50
0
50
100
150
200
time [s]
be
ta [o ]
Vehicle Side Slip Angle
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-4
-3
-2
-1
0
1
2
3
4
time [s]
be
ta [o ]
Vehicle Side Slip Angle
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-60
-40
-20
0
20
40
60
time [s]
de
lta
[o ]Steer Angle
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-2.5
-2
-1.5
-1
-0.5
0
0.5
1
time [s]
r [r
ad
/s]
Yaw Rate
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
0 2 4 6 8 10 12 14 16 18 20-8
-6
-4
-2
0
2
4
6
8
time [s]
a lat [
m/s
2 ]
Lateral Acceleration
noctrlS
sigmaS
beta10S
allS
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Integrated Vehicle Control SystemIntegrated Vehicle Control System
• Technical and commercial considerations restrict the ways that integrated vehicle control systems are implemented in practice
• Limiting total system complexity is a priority
• Layered ‘subsumption’ architectures are particularly applicable to the control implementation, but detailed methodologies are not yet well developed
• Issues of conflict resolution in real-time, may be solved by extending commonly available control techniques
Main ConclusionsMain Conclusions
Integrated Vehicle Control SystemIntegrated Vehicle Control System
Any Questions ?Any Questions ?