Architectures of Automotive Electrical. Nicolas Navet. Can be freely used for teaching Complexity Mastered. Outline

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1 Architectures of Automotive Electrical and Electronics (E/E) Systems Nicolas Navet Teaching slides Can be freely used for teaching Complexity Mastered Outline 1. Architecture of Automotive Embedded Systems What they look like today example of BMW and PSA Constraints in their design the case at Volvo Need for optimizing resource usage (ECU, networks) Possible upcoming architectures 2010 N. Navet INRIA / RTaW - 2 1

2 Electronics is the driving force of innovation 90% of new functions use software Electronics: 40% of total costs Huge complexity: 70 ECUs, 2500 signals, 6 networks, multi-layered run-time environment (AUTOSAR), multi-source software, multi-core CPUs, etc Strong costs, safety, reliability, time to market, reusability, legal constraints! 2010 N. Navet INRIA / RTaW - 3 BMW 7 Series networking architecture [10] Picture from [4] ZGW = central gateway 3 CAN buses 1 FlexRay Bus 1 MOST bus Several LIN Buses (not shown here) Ethernet t is used for uploading code/parameters (End of Line) 2010 N. Navet INRIA / RTaW - 4 2

3 BMW 7 Series architecture wiring harness [10] 27Millions variants Body, audio, doors, battery, wiring harnesses Each wiring harness is tailored to the options Picture from [4] 2010 N. Navet INRIA / RTaW - 5 There are many non technical issues in the design of E/E architecture The case at Volvo in [2] : Influence of E/E architecture wrt to business value? lacks long term strategy Architectural decisions often: lack well accepted process Lack of background in E/E at management level often mechanical background are made on experience / gut feeling (poor tool Lack of clear strategy between in-house and externalized developments support) Technical parameters are regarded as less important than cost for supplier / components selection Vehicle Family Management : How to share architecture and sub-systems between several brands/models with different constraints/objectives? Sub-optimal solutions for each component / function Legal / regulatory constraints 2010 N. Navet INRIA / RTaW - 6 3

4 Proliferation of ECUs raises problems! 50 Number of ECUs (CA AN/MOST/LIN) Mercedes-Benz BMW Audi VW Year Pictures from [3] Lexus LS430 has more than 100 ECUs [wardsauto] 2010 N. Navet INRIA / RTaW - 7 The case of a generalist car manufacturer PSA CAN LAS info-div LIN 25 CAN CAR CAN CONF 20 CAN I/S X X D D2 TG D25 X3 X X W2 PF3 Pictures from [6] The number of ECUs has more than doubled in 10 years 2010 N. Navet INRIA / RTaW - 8 4

5 Optimizing the use of networks is becoming an industrial requirement too Good reasons for optimizing : Complexity of the architectures (protocols, wiring, ECUs, gateways, etc ) Hardware cost, weight, room, fuel consumption, etc Need for incremental design Industrial risk and time to master new technologies (e.g. FlexRay) Performances (sometimes): a 60% loaded CAN network may be more efficient that two 30% networks interconnected by a gateway Some signals must be transmitted on several networks 2010 N. Navet INRIA / RTaW - 9 from [7] Likely upcoming architectures Fewer ECUs but more powerful Multi-core μ-controller Multi-source software Autosar OS strong protection mechanisms Virtualization? ISO dependability standard FlexRay as backbone at BWM in a few years [7] Backbone: High speed CAN : 500Kbit/s FlexRay : 10 Mbit/s Ethernet? Picture from [7] 2010 N. Navet INRIA / RTaW

6 Conclusion Today s automotive E/E architectures are very complex, partly due to carry over It may require one or two car generations to see major changes toward simplified architectures with fewer ECUs, high speed communication backbones, etc Dependability creates new needs: Increasing safety related functions (X by Wire) Certification in the context of ISO N. Navet INRIA / RTaW - 11 References 2010 N. Navet INRIA / RTaW

7 References Automotive Embedded Systems [1] N. Navet, F. Simonot Lion, editors, The Automotive Embedded Systems Handbook, Industrial Information Technology series, CRC Press / Taylor and Francis, ISBN , December [2] P. Wallin, Axelsson, A Case Study of Issues Related to Automotive E/E System Architecture Development, IEEE International Conference and Workshop on the Engineering of Computer Based Systems, [3] T. Nolte, Hierarchical Scheduling of Complex Embedded Real Time Systems, Summer School on Real Time Systems (ETR 09), Paris, [4] H. Kellerman, G. Nemeth, J. Kostelezky, K. Barbehön, F. El Dwaik, L. Hochmuth, BMW 7 Series architecture, ATZextra, November [5] N. Navet, In Vehicle Networking : a Survey and Look Forward, Workshop on Specialized Networks, in conjunction with IEEE ETFA 2009, Mallorca, Spain, September 26, Available at [6] N. Navet, B. Delord, M. Baumeister, Virtualization in Automotive Embedded Systems : an Outlook, talk at RTS Embedded Systems 2010, Paris, France, March, Available at [7] A. Schedl, Goals and Architecture of FlexRay at BMW, slides presented at the Vector FlexRay Symposium, March N. Navet INRIA / RTaW - 13 Questions / feedback? Please get in touch at: nicolas.navet@inria.fr 2010 N. Navet INRIA / RTaW