FlexRay Enabler for Future Automotive System Architectures 3 rd March 2005 Genf Dr. Günter Reichart - BMW Group
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FlexRay
Enabler for Future
Automotive System Architectures
3rd March 2005
Genf
Dr. Günter Reichart - BMW Group
page 2
Requirements driven evolution of functions and systems - mapped on BMW car series
Fun
ctio
ns (
abso
lute
)
Time
5 Series
7 Series
3 Series
5 Series
7 Series
3 Series
5 Series
7 Series
3 Series
Requirements
based
System design
– Change fromanalog tech./digital bus-systems
– n:m-connection– Data rates– Deterministic– Technology– CAN
– Advanced technologies – New design methods– Defined interfaces
+ Driver information+ Driver assistance+ Drive-by-Wire?Df
Df
Df
page 3
Situation snapshot of in-car E/E systems and architectures
� Increasing requirements (legal, functional and safety) demand for further electric/electronic systems
� Mechatronic will replace mechanic (e.g. Drive-by-Wire)
� New functions (e.g. driver assistance) need higher data exchange between functional domains
Environment
Car
ChassisStabilitydomain
Driver Controldomain
Navigationdomain
DMRG
BMW Navigation System ACC HC EDC ABS
CC DBC ASC
DSCm
RDS-TMC
page 4
System Architecture - Complexity Management
Lessons learned …è Complexity by introducing many communication systems in a single car platform
BMW 7 Series – Network
Functional Networking(Customer View)• Communication• Driver Information• Driver Assistance
Functional Networking
(Technology)• by wire
+ +
byteflight CANCANMOSTCAN
à Locally "open" Architecture
Inter-dependencies
Goal:
Reduction of variants in
specific communication
systems
+
Common
Open System
Architecture Forward
Standardization
page 5
Requirements for a common communication system mapped to the automotive application domains
• X-by-wire systems
• Chassis systems
• Powertrain systems
• Future backbone for open systems architectures
Dependability and fault containment
Determinism
High bandwidth
Flexibility and high bandwidth
è
è
è
è
FlexRayR
equ
irem
ents
CommunicationsControl
LIN
MOST
CAN
page 6
Requirements for Open System Architecture
� Displacement of functional modules beyond domain boundaries
� Strategy for reduction in technology variety is mandatory and it requires new feature integration
� Flexibility of hardware
� Approach must be based on future standards
� Standardized interfaces
� Support by development methods and tools
page 7
FlexRay History
Experience in BMW / DC / Bosch / GM Experience in BMW
1998 Analysis: CAN / TTP / MOST / byteflight
Start of communication between BMW and DaimlerChrysler
Realization: Future requirements are not fulfilled by existing protocols
Consequences: Start of cooperation
FlexRay Consortium founded by BMW, DaimlerChrysler, Motorola, Philips
Realization of FlexRay System together with semiconductor industry
Bosch joins FlexRay Consortium
General Motors joins FlexRay Consortium
Ford Motor Company, Mazda and Fiat join as Premium Associate Members
Volkswagen joins the FlexRay Consortium
Toyota, Honda, Nissan join the FlexRay Consortium as PAMs
Release of FlexRay Specifications, SW & tools available to the general public
PSA, Renault join the FlexRay Consortium as Premium Associate Members
1999
Since 1999
2000
Since 2000
10/2000
09/2001
04/2002 - 10/2002
Q3/2003
Q4/2003
06/2004
Q3/2004
page 8
Scope of the Consortium
The scope of the Consortium is to develop jointly an innovative communications network of very high quality which consists of the complete communication infrastructure and includes inter alia the specifications for the serial communications protocol, the transceiver, the hardware and software interfaces and conformance/certification procedures. This will serve as the basis for the development, production and implementation of certain communications networks for automotive applications.
The ultimate objective of the Consortium is the factual industry-wide recognition of a new standard for a deterministic automotive network which shall be open to use and development by third parties.
page 9
Core Members
BMW Group
Bosch
DaimlerChrysler
General Motors
Freescale (Motorola)
Philips
Volkswagen
Development Members
CadenceCANwayCapeWareCardecCRSTDECOMSYSdSpaceETASIXXATMicroSysNational InstrumentsNSI3SOFTSoftingSystemATecWingsTZMVector InformatikVolcanoWeise GmbH
Associate Members
AMSATMELAvidyneBerataEADSElmosESGEsterelFujitsuHellaHitachiHyundaiInfineonMitsubishiNECNidecPacificaPorscheRenesasRWTÜVSiemensVDOSPST MicroSubaruSumitomoTexas InstrumentsThyssenKrupp AutomotiveTRWVisteonYazaki
Premium Associate Members
ContiTeves
Delphi
Denso
Fiat
Ford Motor
Honda
Mazda
Nissan
Peugeot Citroen
Renault
Toyota
Tyco Electronics
Volvo
De-facto Automotive Standard
page 10
Structure of the Consortium - Mechanisms
Executive Board
Technical Project leaderSteering Committee
AdministratorStrategy,
Scientific, TechnicalSpokesperson
Technical Working Groups
page 11
Working Group Structure
Requirement Group
Protocol GroupPhysical Layer
Group
Test Group Scientific Proof Group
FMEA Group
Verification
Requirement Spec
FlexRay Specs
Feedback
Feedback
page 12
FlexRay - the communication system (1/3)
Features� Forward-standardization – an objective from the beginning§ OEMs, TIER1s and semiconductor vendors
are represented in the FlexRay consortium
�Bandwidth§ No limitation due to protocol mechanisms§ Current design focus: 10 Mbit/s
�Scalability§ Single channel / Dual channel§ Mixed configuration
Host
FlexRayCommunication
Controller
BGA BDA BGB BDB
Channel BChannel A
BD: Bus DriverBG: Bus Guardian (optional)
page 13
�Flexibility§ Open to many network topologies§ Electrical and optical Physical Layer§ Dynamic and static segments in communication cycle§ Frame ID
CRC CRC
24 bits
DataFrame ID
7 bits
0 ... 254 Bytes
Cycle CRC
FlexRay Frame 5 + (0 ... 254) + 3 Bytes
Length
12 bits 6 bits
Syn
c B
it
11 bits 16 bits
Message IDHeaderCRC
Nu
ll F
ram
e In
dic
atio
n
Header Segment Payload Segment Trailer Segment
Data Data
Header CRCCovered Area
NM
ind
icat
ion
Res
erve
d
1111
Data
NM
Frame ID:Equivalent to Slot number; implicitly denotes the sender
FlexRay - the communication system (2/3)
page 14
� Deterministic§ Stringent deterministic by TDMA media access (Time Division Multiple
Access) in static segment§ Limited deterministic by FTDMA media access (Flexible Time Division
Multiple Access) in dynamic segment
� Safety§ Distributed Clock Synchronization
- Offset and Rate Correction§ Bus Guardian§ CRC
- Header CRC- Frame CRC- Hamming Distance of 6
FlexRay - the communication system (3/3)
page 15
FlexRay Bus Access Method
Communication Cycle 1
Static Segment Dynamic Segment
1 3 4 5 6
1 2 3 5 6
Channel A
Slot
7
7
8 10
8 139
...
...
Node EID: 6, 13
Node AID: 1, 5,10
Node BID: 2
Node CID: 3, 8
Node DID: 4, 7
Cycle 2
Static
9
Channel B
time
page 16
FlexRay Time Triggered CommunicationComposability in the Time Domain
A B C D F G H I K L 1 2 3 4 5 6
D H 2 4
B F I L 1 6
A C G K 3 5
Static Segment Dynamic Segment
AA
SystemSystem--IntegrationIntegration
BB
CC
Frame
Time Slot
Communication Cycle
Dynamic Segment
Dynamic Segment
Dynamic Segment
Static Segment
Static Segment
Static Segment
ECU
page 17
Benefits of the FlexRay Technology
• Provide a communication infrastructure for future generation high-speed control applications in vehicles such as advanced powertrain, chassis, and by-wire systems.
� High bandwidth (net data rate 5 Mbps at gross 10 Mbps), flexible use of bandwidth
� Deterministic behavior (guaranteed transmission time for frames in the static segment)
� Synchronization of tasks in distributed control systems
� Cycle times < 2 ms
� Reliable data communication
� Facilitation of system integration
� Reserves for future functional extensions
� Possibility to implement future real Drive-by-Wire functions without mechanical back-up
page 18
FlexRay Roadmap
page 19
Standard-Structure model with FlexRay as underlying Communication Layer
Operating SystemApplication
A
Diagnosis
Transport Layer
Message-Mgt.
HW-Driver
Net-work Mgt.
FlexRay Controller + Transceiver (HW)
EEPROM DriverCon
figur
atio
n vi
a D
atab
ase
ApplicationB
ApplicationMgt.
...
Middleware
API Interfaces
FlexRay
(CAN,
MOST,
Other)
Fixed APIs for each possible technology
Bus (in certain topologies)
Librariesof Standards
(floating point, integer, type conversion)
HW Abstraction-Layer (I/O)
FTcom
page 20
Activities around the FlexRay protocol
�Physical Layer development proceeding in parallel�HW features to support future network management
concepts§ ie. Network Management Indication Bit and Network Management Vector
�OSEKtime§ OSEK enhancement for time triggered operation
� FTcom: Fault Tolerant communication layer for OSEK architecture§ specification and pilot-implementations available
� FIBEX (FIeld Bus EXchange format)§ XML-exchange format based on a generic bus model enables interoperability
between databases and development tools
Enabler for OSAREnabler for OSAR
page 21
Summary
• FlexRay is a communication system targeted at high-speed control applications in vehicles such as advanced powertrain, chassis, and by-wire systems.
• FlexRay supports these applications by providing architectural flexibility through scalability and functional alternatives.
• FlexRay is expected to be the de-facto communication standard for high-speed automotive control applications.
www.flexray.com
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